A Systematic Compilation of IUCN Red-listed Threatened Plant Species in Nigeria

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There exist varying lists of "endangered" plants published by different authors in Nigeria, which are characterised by discrepancies, while the level of threats to these listed species was not defined. Therefore, most of these lists have limitations in their use for conservation management of indigenous plants in Nigeria. This article was written to compile the list of Nigerian native plants that have been evaluated in the IUCN Red list of Threatened Species, making references to the CITES appendices. A list of 164 plants was compiled from versions 2012.2 and 2013.2 of the IUCN Red list. These 164 plants comprise 16 "critically endangered", 16 "endangered" and 132 "vulnerable" plants; while the list is made up of 120 trees, 16 shrubs, 20 herbs, 6 epiphytes and 2 lianas. Rubiaceae has the highest number of species representatives; while 21 of the entire list are strictly endemic to Nigeria. Varying threats were reported for the species including oil exploration, endemism, land use change, insect damage, genetic erosion, poor germination and growth among others. Recommendations include development of Nigeria's national red list, effective protected area management, tree domestication, ex-situ conservation, community-based natural resources management and evaluation of other suspected "endangered" plants in Nigeria.

CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I International Journal of Environmental Sciences Vol. 3 No.3. 2014. Pp.104-133 ©Copyright by CRDEEP. All Rights Reserved SJIF Impact Factor (2013): 4.183 Vol. 3 No. 3 ISSN: 2277-1948 Full Length Research Paper A Systematic Compilation of IUCN Red-listed Threatened Plant Species in Nigeria Borokini, T.I National Centre for Genetic Resources and Biotechnology, P.M.B 5382, Moor Plantation, Ibadan, Nigeria . Abstract There exist varying lists of “endangered” plants published by different authors in Nigeria, which are characterised by discrepancies, while the level of threats to these listed species was not defined. Therefore, most of these lists have limitations in their use for conservation management of indigenous plants in Nigeria. This article was written to compile the list of Nigerian native plants that have been evaluated in the IUCN Red list of Threatened Species, making references to the CITES appendices. A list of 164 plants was compiled from versions 2012.2 and 2013.2 of the IUCN Red list. These 164 plants comprise 16 “critically endangered”, 16 “endangered” and 132 “vulnerable” plants; while the list is made up of 120 trees, 16 shrubs, 20 herbs, 6 epiphytes and 2 lianas. Rubiaceae has the highest number of species representatives; while 21 of the entire list are strictly endemic to Nigeria. Varying threats were reported for the species including oil exploration, endemism, land use change, insect damage, genetic erosion, poor germination and growth among others. Recommendations include development of Nigeria’s national red list, effective protected area management, tree domestication, ex-situ conservation, community-based natural resources management and evaluation of other suspected “endangered” plants in Nigeria. Keywords: Threatened taxa, endangered, IUCN, CITES, Nigeria, biodiversity Introduction Each country represents a large number of plant and animal species, each with their biological significance and hence, the need to conserve them. However, if all these biodiversity are to be conserved appropriately, it would take decades of intensive work and huge financial and land resources. In addition to that, the highest rates of biodiversity in the world are found in tropical regions populated by developing countries, which do not have adequate technical and financial resources to manage all these species. Furthermore, all these species have widely ranged population, which are as a result of widely ranged trends of human exploitation, growth forms and varying bio-geographical distribution among many others. Therefore, there is the need for setting priorities for conservation efforts for these species, with more attention to the ones whose population have reduced drastically, species with narrow range of biogeographical distribution, endemic species and those who belong to monospecific genera. These species that require urgent conservation efforts are called threatened or endangered species. A threatened species is a population of organisms which is at risk of becoming extinct. Nigeria is unique for its widely varying ecological regions and thousands of plant species within her political boundaries. A total of 7,895 plant species from 338 families and 2,215 genera have been identified in Nigeria (Table 1) (Federal Ministry of Environment, 2006), including about 1,489 species of micro-organisms. Furthermore, the Biodiversity Country Study estimated that there are 3,423 fungi species in Nigeria, 134 plankton species, more than 500 virus species, more than 848 algae species and 55 bacteria species in Nigeria (FEPA, 1992). In Cross River state alone, the Forestry Research Institute of Nigeria lists 85 endangered tree species, and many of these are endemics, found only in this region. Five of them are monospecific, that is, the only representative of a particular genus found in the world (Oguntala, et al, 1996). Table 1: Inventory of Plant Species in Nigeria Group of Plants No. of families 67 Algae Lichens 26 Fungi (Mushrooms) Mosses Liverworts 27 Pteridophytes 2 Gymnosperms 2 Chlamydosperms 42 Monocotyledons 172 Dicotyledons TOTAL 338 Source: Nigeria’s First National Biodiversity Report, FMEnv. (2006) 104 No. of Genera 281 14 60 13 16 64 3 2 376 1396 2215 No. of Species 1335 17 134 16 6 165 5 6 1575 4636 7895 Online version available at: www.crdeep.com CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Many papers have been published about plant species by many researchers in Nigeria and in trying to justify the significance of their studies; they labelled the studied plant a threatened species in Nigeria, without proper literature sources to the claim. In addition, several Nigerian authors have produced many lists of species that were assumed to be threatened, some of which are true, but many others were not justified. The relevant Government documents and national reports were simply estimates compiled by a group of experienced Nigerian scholars and representatives of Research Institutes that have relevant national mandate. One of such was the comprehensive list of over 200 threatened plants in Nigeria, compiled and reported in the Nigeria Country Report on FAO International Technical Conference on Plant Genetic Resources in Leipzig in 1995 (FAO, 1996); while Gbile et al. (1981, 1984) published endangered and rare species in Nigeria, based on plant records in the Forestry Herbarium, Ibadan (FHI) of the Forestry Institute of Nigeria. In addition, FEPA (2007) compiled another list of 18 endangered plants in Nigeria. During the 80th anniversary of the Nigerian Field Society in 2010, a special edition of their journal was published, with the focus on endangered species in Nigeria. Okafor (2010) and Isichei (2010) separately listed another group of endangered plant species. Okafor (2010) explained that the scope or range of endangered plant species include (i) wild species which are restricted to habitats; (ii) widespread but intensively harvested and utilized; (iii) so called uneconomic species; (iv) recalcitrant species which lose viability early; (v) underutilized or neglected species; (vi) primitive cultivars and wild relatives of crop plants. So far, majority of these compilations of endangered species were done based on local records and personal knowledge and information gathered by the authors, but are characterised by discrepancies and irregularities, thus limiting their use for conservation management of Nigerian flora. For instance, Foresters believe and reported that all forest tree species in Nigeria are threatened due to the high rate of uncontrolled exploitation of forest resources in Nigeria (Adekunle 2006, Famuyide et al. 2012, Ouinsavi et al. 2009). But the IUCN classification for Milicia excelsa, one of the highly priced timber species in Nigeria is “near threatened”, indicating that the species is not even at risk (IUCN, 2014). To support this, a recent study in Ibadan Metropolis alone sighted and reported over 100 stands of Milicia excelsa (Borokini et al., 2013), while an estimated several thousands of Milicia excelsa stands were sighted in Ondo state during the author’s reconnaissance survey in 2012 and 2013. Furthermore, M. exclesa is widely distributed in the entire forest and Guinea savannah ecoregions of Nigeria. This misinformation could lead to misplacement of priorities in conservation efforts in Nigeria. While it is important to note that global category for a species may be different from the national category for that species. Many countries in the world have produced their national red list of all plant and animal species in their countries, but Africa is lagging behind in this regard, visit to the National Red list website on May 8, 2014 revealed that only 2 African countries – Benin Republic and South Africa – have produced and published their national red list of species. For other countries, they are expected to rely on IUCN red list of threatened species or any other globally recognised classification for effective conservation management. The IUCN Red List Categories and Criteria are widely accepted as the most objective and authoritative system available for assessing the global risk of extinction for species (De Grammont and Cuarón 2006, Lamoreux et al. 2003, Mace et al. 2008, Rodrigues et al. 2006). It began in the 1960s with the production of the first Red Data Books (Fitter and Fitter 1987) and has since evolved from multiple lists and books dedicated to animal groups or plants into a unique comprehensive compendium of conservation-related information (Vie et al., 2008). The general aim of the IUCN Red List Categories and Criteria is to provide an explicit, objective framework for the classification of the broadest range of species according to their extinction risk (IUCN, 2004). The specific aims of the Red List are to: 1. Provide a system that can be applied consistently by different people; 2. Improve objectivity by providing users with clear guidance on how evaluate different factors which affect the risk of extinction; 3. Provide a system which will facilitate comparisons across widely different taxa; 4. Give people using threatened species list a better understanding of how individual species were classified. It is based on an objective system allowing assignment of any species (except micro-organisms) to one of eight Red List Categories (Figure 1) based on whether they meet criteria linked to population trend, size and structure and geographic range (Mace et al. 2008). For example, a taxon is considered endangered if there is a reduction in population size (>80% in the last 10 years or projected reduction in the future) in numbers (estimated to be less than 2,500 mature individuals) and if projected extinction of at least 20% within 20 years (IUCN, 2004). The IUCN Red List also provides extensive information on species’ taxonomy (classification of species), conservation status, geographic distribution, habitat requirements, biology, threats, population, utilization, conservation actions and spatial distribution maps. Only about 2.5% of the world’s estimated 1.8 million described species have been assessed for The IUCN Red List so far; therefore the number of reported threatened species is much less than the true number at serious risk of extinction. The IUCN Red List is, nevertheless, by far the most complete global list of such species available. By 2008, 44,837 species have been assessed; at least 38% of these have been classified as threatened and 804 classified as Extinct (Vie et al. 2008). One of The IUCN Red List’s main purposes is to highlight those species that are facing a high risk of global extinction. In the absence of a national red list for Nigerian species, this study was conducted to compile the list of threatened plant species in Nigeria from the IUCN red list of threatened species. 105 Online version available at: www.crdeep.com CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Figure 1: Structure of the IUCN Red List Categories of conservation status of species (Vie et al. 2008) Methodology The IUCN Red List of Threatened Species versions 2012.2 and 2013.2 (IUCN 2013, 2014) were screened between 2012 and 2014 to compile the names of details of plant species that are recorded from Nigeria. The names, family, conservation status, distribution range and growth habit of the identified threatened plants were noted. Reference was also made to the compilations made by Glenn (2006) on Earth’s Endangered Website and JSTOR Plant collections (www.plants.jstor.org) to make additions to the distribution range and plant family names of some of the threatened plants. Results The results indicated that 164 threatened plant species were found in Nigeria (Table 1), of which 16 are critically endangered (CR), 16 were endangered (EN) and the remaining 132 were vulnerable (VU). Furthermore, 21 (12.8%) of them were reported to be endemic to Nigeria, while the rest were naturally distributed beyond Nigerian borders, most of which are located in West Africa. The endemic species were found mainly in Eket (10), Oban Division of Cross River National Park (8) and Degema (3) among other locations, all of which are in the forest ecoregion of Nigeria. The entire 164 threatened plants comprise 120 trees, 16 shrubs, 20 herbs, 6 epiphytes and 2 lianas (Table 1), while they spread across 53 plant families. Rubiaceae has the highest number (18) of species representatives among the 164 threatened plants, followed by Caesalpiniaceae (14),Meliaceae (12), Papilionaceae (11), Annonaceae and Sterculiaceae (9 each) among others. The reported threats noted for these threatened plants include crude oil explorations and spillage (especially in Eket), land use change to agriculture, heavy exploitation due to logging and timber extraction (noted in the unprotected areas surrounding the Cross River National Park and in other locations in Nigeria), local/anthropological induced fire, habitat destruction/loss – due to forest clearance for development projects, poor/slow growth rate of species, mining, poor seed viability, large-scale deforestation, water pollution, dam construction, grazing, cattle trampling, urban expansion and population pressure, flooding, insect attack on seedlings, genetic erosion, low range of distribution and endemism, palm wine tapping, drought, reduction in seed disperser populations, invasive species, die-backs, bark harvesting and over exploitation for fuelwood, chewing sticks among other threats. In addition to these 164 threatened species, Cedrela odorata L. (Meliaceae) and Shorea roxburghii G. Don (Dipterocarpaceae) are both tree species, classified as vulnerable and endangered in their native ranges respectively, but these 2 species were introduced to parts of West Africa and have become established in the region. Cedrela odorata is also listed in CITES Appendix III (CITES, 2012). The native range of Cedrela odorata include Antigua and Barbuda; Argentina; Barbados; Belize; Bolivia, Plurinational States of; Brazil; Cayman Islands; Colombia; Costa Rica; Cuba; Dominica; Dominican Republic; Ecuador; El Salvador; French Guiana; Grenada; Guadeloupe; Guatemala; Guyana; Haiti; Honduras; Jamaica; Mexico (Quintana Roo); Montserrat; Nicaragua; Panama; Peru; Saint Kitts and Nevis; Saint Lucia; Suriname; Venezuela. However, the native range of Shorea roxbughii include Cambodia; India (Andhra Pradesh, Karnataka, Kerala, Tamil Nadu); Lao People's Democratic Republic; Malaysia (Peninsular Malaysia); Myanmar; Thailand; Viet Nam. 106 Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Table 1: List of Nigerian threatened species in the IUCN Red List of Threatened Species versions2012.2 and 2013.2 S/N Name Status Remarks Nativity Acanthopale decempedalis VU The cyclical mass-flowering habit of this species results in large fluctuations in mature Cameroon; 1 C.B Clarke (Acanthaceae) populations, making it susceptible to short-term stochastic change, for example local fire Equatorial Guinea events or landslides which could decimate seedling populations. Clearance for (Bioko); Nigeria agriculture is widespread in the Bamenda Highlands, threatening these populations. (Cross River) Achyranthes talbotii Hutch VU Loss of habitat is still a major threat to this species. The proposed conversion of lowland Cameroon, Nigeria 2 & Dalz. (Amaranthaceae) forest around Mt Cameroon to plantation is likely to threaten the plant communities of the rivers that drain the area, such as the Onge, an important site for this taxon, through flooding and excessive silting of their habitat. Illegal logging for timber in lowland Bakossi is likely to have a similar impact. Acioa eketensis De Wild. CR As with A. dichotoma, this species is poorly known and endemic to Eket in south-east Eket, Nigeria 3 [Syn: Dactyladenia eketensis Nigeria. The effects of oil exploration operations have caused the extensive, if not (De Wild) Prance & F. complete, destruction of the habitat. White] (Chrysobalanaceae) Acioa dichotoma De Wild. CR A species for which there is little information. Like A. eketensis, it is apparently endemic Eket, Nigeria 4 [Syn: Dactyladenia to the Eket area. Oil exploration operations have extensively, if not completely, dichotoma (De Wild) Prance destroyed the habitat. & F. White] (Chrysobalanaceae) Khaya anthotheca (Welw.) VU An important source of African mahogany. It is heavily exploited, particularly in East Angola (Angola); 5 C. DC. (Meliaceae) and West Africa. Regeneration is poor in places, especially where parent trees are scarce, Cameroon; Congo; and serious genetic erosion is believed to have occurred. Congo, The Democratic Republic of the; Côte d'Ivoire; Ghana; Liberia; Malawi; Mozambique; Nigeria; Sierra Leone; Tanzania, United Republic of; Uganda; Zambia; Zimbabwe Khaya grandifoliola C. DC. VU Exploitation is heavy: extraction of mature individuals from subpopulations has been Benin; Congo, The 6 (Meliaceae) comprehensive. Regeneration is poor away from parent individuals and is best at the Democratic savannah-forest boundary. Republic of the; Côte d'Ivoire; Ghana; Guinea; Nigeria; Sudan; Togo; Uganda 107 Habit Shrub Herb Tree Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 Khaya ivorensis A. Chev. VU Levels of exploitation are very high. Little regeneration takes place after disturbance. 7 (Meliaceae) Individuals reach a seed-producing age at 30 years, although large seed crops appear only at three to four year intervals. 8 Khaya senegalensis (Desr.) A. Juss. (Meliaceae) VU 9 Baillonella toxisperma Pierre (Sapotaceae) VU 10 Pericopsis elata (Harms) van Meeuwen (Papilionaceae) EN 11 Lovoa trichilioides Harms (Meliaceae) VU ISSN: 2277-1948 Angola (Angola); Cameroon; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria Logging and local exploitation are largely uncontrolled and poorly monitored. In Benin; Burkina northern parts of the range exploitation may be leading to genetic erosion. Natural Faso; Cameroon; regeneration from the seed is poor but does occur from suckers Central African Republic; Chad; Côte d'Ivoire; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Mali; Niger; Nigeria; Senegal; Sierra Leone; Sudan; Togo; Uganda The species is overexploited for its timber and is seriously declining in large parts of its Angola (Angola, range. It is the second most important exported wood in Gabon. Amongst other local Cabinda); uses the tree produces edible oil which can fetch high market prices. Cameroon; Congo; Congo, The Democratic Republic of the; Gabon; Nigeria Since 1948 trade in the timber has soared. Levels of exploitation have been unsustainable Cameroon; Congo; in all countries and the species' habitat has declined. Regeneration is insufficient to Congo, The replace lost subpopulations. The species is currently listed in CITES Appendix II. Democratic Republic of the; Côte d'Ivoire; Ghana; Nigeria Germination success is somewhat limited by short-lived seeds which are heavily Angola (Angola); predated. Exploitation rates are high. It is one of the two principal timber species in Cameroon; Congo; Congo. Congo, The Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria; Sierra Leone; Tanzania, United 108 Tree Tree Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 12 Afrofittonia silvestris Lindau (Acanthaceae) VU 13 Afrothismia winkleri (Engl.)Schlechter (Burmanniaceae) CR 14 Afzelia africana Sm. (Caesalpiniaceae) VU 15 Allexis cauliflora (Oliver) Pierre (Violaceae) Allexis obanensis(Baker f.) Melch. (Violaceae) VU Allophylus bullatus Radk. (Sapindaceae) VU 16 17 VU CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Republic of; Uganda Forest clearance is the main threat to the survival of the species. However, higher Cameroon; altitude sites discovered in Bakossi are less threatened. Equatorial Guinea (Bioko); Nigeria (Cross River) Known from only seven locations throughout its range, this species is probably extinct at Cameroon, Nigeria Mt Cameroon, the type locality, since it has not been seen there in about 100 years, despite considerable searching. The species was previously assessed as CR, but since then new sites have been discovered, at Korup and at Banyang Mbo, both in S.W. Province, Cameroon; accordingly a new assessment is made here. The extent of occurrence is less than 100 km², is severely fragmented and there is continuing decline in habitat quality due to forest clearance for timber and agriculture. The Nigerian material has been suggested as belonging to a different, new, unpublished species. The main threat to the species is forest clearance for agriculture, timber and plantations. Exploitation of the timber for the international market. Benin; Burkina Faso; Cameroon; Central African Republic; Chad; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Ghana; Guinea; Guinea-Bissau; Mali; Niger; Nigeria; Senegal; Sierra Leone; Sudan; Togo; Uganda Extensive logging, mining and clearing of the forest for cultivating crops have caused Ghana, Nigeria considerable declines in the habitat. A rarely recorded small tree of the violet family. It is known from the contiguous forest Cameroon, Nigeria area covered by the Oban Division of the Cross River National Park in Nigeria and Korup National Park in Cameroon. Areas outside the parks have been heavily deforested and cleared for agriculture and commercial crops. Part of the population occurs in the Cross River National Park in Nigeria and Korup National Park in Cameroon. This understorey tree of upper submontane to montane forest, while secure at Mt SE Nigeria; Cameroon and at Mt Kupe, has lost large tracts of its habitat in recent decades in the Cameroon; São Bamenda Highlands. Over 30% of its overall habitat is estimated to have been lost in the Tomé and Principe last 100 years. Threatened by clearance of forest for agriculture and wood, particularly in (Cameroon line 109 Liana Herb Tree Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 the Bamenda Highlands of Cameroon, once probably the main area for A. bullatus. Study mountains). of one area here (Moat in Cheek et al. 2000) showed that 25% of forest was lost between 1987 and 1995. Aneilema silvaticum Brenan VU There is assumed to be continuing due to clearance of lowland forest for timber and/or Cameroon; Congo, 18 (Commelinaceae) agriculture across the entire range. The Democratic Republic of the; Nigeria Angraecum pyriforme VU Clearance of forest for conversion to agricultural small-holdings or plantations, Cameroon; Côte 19 Summerh. (Orchidaceae) particularly threatening the Nigerian and Ivory Coast sites where clearance has been d'Ivoire; Nigeria widespread in recent decades although the Tai Forest is thought to remain intact. It would therefore appear to have a small area of occupancy and there is continuing decline due to clearance of forest for conversion to agricultural small-holdings or plantations. Angylocalyx talbotii Baker f. VU Known only from six sites. This species is threatened with extinction at all its known Nigeria, Cameroon 20 (Papilionaceae) sites, except at Korup N.P., by forest clearance for logging and agriculture. Threatened by forest clearance for logging and agriculture. Small-holder agriculture was found to be eating into the part of the Mungo River F.R. where the species was seen most recently. Market gardening at the Bambuko F.R. has destroyed much habitat there and forest around Mt Cameroon is also under threat (Cable and Cheek 1998). Anopyxis klaineana (Pierre) VU Habitat loss and exploitation are serious threats in most places. Seeds have poor viability Cameroon; Congo; 21 Engl. (Rhizophoraceae) and regeneration has been observed to be poor. Côte d'Ivoire; Ghana; Liberia; Nigeria; Sierra Leone Anthocleista microphylla VU Forest clearance for agriculture and wood; it may already have been lost from both Ghana, Nigeria, 22 Wernham (Loganiaceae) Nigerian sites (Oban and Obudu) since significant forest loss has occurred there in recent Cameroon, decades. Although it is fairly common at Kupe village, it occurs there at such low Equatorial Guinea altitudes (ca. 800 m) that it is vulnerable to agricultural expansion. (Bioko), Sao Tome and Principe Anthocleista scandens Hook. VU It is estimated that, over the last 100 years, over 30% of the habitat of this species, Ghana, Nigeria, 23 f. (Gentiananceae) mostly in the Bamenda Highlands and Bamboutos, has been lost due to forest clearance. Cameroon, Forest clearance for agriculture and wood, particularly in the Bamenda Highlands, where Equatorial Guinea forest loss has been running at 25% over eight years at one sample area (Moat in Cheek (Bioko), Sao Tome et al. 2000). and Principe Anthonotha nigerica (Bak.f.) VU A small forest tree with an apparently disjunct distribution, occurring in the remaining DRC, Nigeria 24 J.Léonard (Caesalpiniaceae) forest in south-east Nigeria and also in Democratic Republic of Congo, where the extent of its occurrence is not at present known. In Nigeria the largest, if not only, intact population occurs in the Oban Division of the Cross River National Park. Deforestation in the region has been extensive. Anthonotha obanensis VU The population is well protected but logging and conversion of land to agriculture are Nigeria: Sapoba FR 25 (Baker f.) J. Léonard extensive in the surrounding area. It is endemic to Nigeria. (Edo State); Eket (Caesalpiniaceae) (Akwa Ibom State); 110 Herb Epiphyte Tree Tree Tree Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 26 Antrocaryon micraster A. Chev. & Guillaum. (Anacardiaceae) VU 27 Afzelia bipindensis Harms (Caesalpiniaceae) VU 28 Albizia ferruginea (Guill. & Perr.) Benth. (Mimosaceae) VU 29 Autranella congolensis (De Wild.) A. Chev. (Sapotaceae) Baphia dewildeana Soladoye (Papilionaceae) CR Baphia latiloi Soladoye (Papilionaceae) VU 30 31 VU CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Oban Division, Cross River National Park (Cross River State) Emergent species in semi-deciduous forests. It regenerates in canopy gaps. It performs Cameroon; Congo, less well in burnt or heavily disturbed forests. The Democratic Republic of the; Côte d'Ivoire; Ghana; Nigeria; Sierra Leone; Uganda It is heavily exploited throughout its range for its valuable timber. In some areas they are Angola (Angola); reported to be few seed trees remaining. Cameroon; Central African Republic; Congo; Congo, The Democratic Republic of the; Gabon; Nigeria; Uganda A widespread and often common timber species which has suffered heavy exploitation. Angola (Angola); Mature individuals are scattered and becoming rare in places. Benin; Cameroon; Central African Republic; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Nigeria; Senegal; Sierra Leone; Togo; Uganda Heavy exploitation for the timber is the main cause of its decline. Cameroon; Congo; Gabon; Nigeria A forest species scattered within an area extending from south-east Nigeria into Cameroon. Its habitat outside protected areas has experienced heavy declines because of logging and clearing for commercial and subsistence agriculture. A small forest tree which occurs within a range extending from south-east Nigeria just into Cameroon. There has been extensive deforestation in the surrounding area. 111 Tree Tree Tree Tree Cameroon; Nigeria Tree Cameroon; Nigeria Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Subpopulations in the Oban Hills, in Cross River National Park, are protected. Baphia obanensis Baker f. VU A morphologically unusual and rare Baphia species, which is confined to an area Cameroon; Nigeria 32 (Papilionaceae) extending from south-east Nigeria into adjacent parts of Cameroon. Unprotected forest has been heavily logged and taken over for cultivation. The Nigerian population occurs in the Oban Hills, in Cross River National Park. Belonophora talbotii VU The species range appears to be confined to the Oban Hills in Cross River National Park. Nigeria: Oban 33 (Wernham) Keay Large-scale deforestation and clearance for crops have taken place extensively outside Division, Cross (Rubiaceae) the park boundaries. River National Park Berlinia hollandii Hutch. & EN Apparently endemic to south-eastern Nigeria. Unprotected areas have been heavily Nigeria: Itu (Akwa 34 Dalziel (Caesalpiniaceae) logged and cleared for agriculture. Ibom State); Oban Division, Cross River National Park (Cross River State). Brachystegia kennedyi VU Forest outside protected areas has significantly declined because of large-scale logging Cameroon, Nigeria 35 Hoyle (Caesalpiniaceae) and clearing for agriculture. Brachystegia nigerica Hoyle VU Deforestation and clearance for crops have been comprehensive outside protected areas. Cameroon, Nigeria 36 & A. Jones (Caesalpiniaceae) Brachystephanus longiflorus VU The paucity of collections from Cameroon despite extensive survey work, and its Cameroon; 37 Lindau (Acanthaceae) absence from the Bakossi Mountains, Manengouba and the Bamenda Highlands, indicate Equatorial Guinea that this species is highly restricted in range and there is continued habitat loss across the (Bioko); Nigeria range. Forest clearance threatens the Nigerian population. Brillantaisia lancifolia VU Herb growing on waterfall rocks. The plant is specialist in terms of ecology (rocks in Gabon; Nigeria 38 Lindau (Acanthaceae) waterfall), therefore its area of occupancy (AOO) is expected to be very narrow. There are only two locations and the species is potentially threatened by water pollution and dam construction. It is therefore listed as Vulnerable. This species is restricted to south Nigeria (Oban district) and Gabon (Sierra del Crystal). Cleistopholis staudtii Engl. VU Through some parts of its range (Nigeria, C.A.R., Kumba), forest loss has been extensive Cameroon; Central 39 & Diels (Annonaceae) since the last collections were made and the species may no longer occur at those places. African Republic; Clearance of forest for timber, followed by agriculture. Gabon; Nigeria Cryptosepalum diphyllum EN Records of this forest species are known only from south-east Nigeria. It is not known Nigeria: Ukpon 40 Duvign. (Caesalpiniaceae) from the Oban Division of the Cross River National Park. Forest outside protected areas River FR, Ekang is almost completely cleared and planted with commercial or subsistence crops. river, Obubra (Cross River State) Crotonogyne strigosa Prain VU Threatened by ongoing habitat loss for agriculture and the upgrading of a major road Cameroon; Nigeria 41 (Euphorbiaceae) through the middle of the range. Logging of forest followed by agriculture, amplified by ongoing, massive upgrading of the Kumba-Mamfe road through the heart of its range. Crateranthus talbotii Baker VU An unusual small tree, which occurs in swamp forests and submontane forest near Cameroon; Nigeria 42 f. (Lecythidaceae) streams; 200–1,000 m alt. It is being suspected that over 30 % of its habitat has been lost in the last 100 years, largely in Nigeria. Forests outside protected areas have largely been logged and cleared for commercial crops and subsistence farming. 112 Tree Tree Tree Tree Tree Shrub Herb Tree Tree Shrub Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Crassocephalum bauchiense VU This erect blue-flowered herb is threatened by clearance of trees for agriculture and Cameroon; 43 (Hutch.) Milne-Redh. wood. Equatorial Guinea (Asteraceae) (Bioko); Nigeria Craibia atlantica Dunn. VU Its forest habitat, particularly dry forest in Ghana, has experienced serious reductions in Cameroon; Côte 44 (Papilionaceae) extent, mainly because of agricultural expansion, settlement and fires. d'Ivoire; Ghana; Nigeria Chazaliella obanensis VU Most of the stands of this species occur below 1,000 m alt. and so are particularly Cameroon; Nigeria 45 (Wernham) Petit & Verdc. vulnerable to expansion from agriculture. It is estimated that 30–50% of the global (Rubiaceae) habitat of this species is likely to be lost in the next ten years. Threatened by clearance of forest for expansion of agriculture. Crotalaria bamendae VU The current threats to this species are unknown, however, fire and grazing may adversely Angola (Angola); 46 Hepper (Papilionaceae) affect the population. Cameroon; Nigeria Crotalaria ledermannii VU Current threats to the species are unknown, but conversion of land to cultivation and Cameroon, Nigeria 47 Baker f. (Papilionaceae) grazing areas, trampling, or fires may be the main sources. This is an annual or shortlived perennial species and a deleterious change in the habitat or poor seed set in one year could reduce the population within 12 months. Chassalia laikomensis CR About 95% of the original forest cover of the Bamenda Highlands has been lost to e.g., Cameroon; Nigeria 48 Cheek (Rubiaceae) agriculture and there have been similar losses at Mambilla and Muanenguba. Clearance of forest primarily for agricultural expansion. Cassipourea eketensis Baker CR A botanical survey of Eket area is required to ascertain whether the species is now Nigeria: Eket, Oban 49 f. (Rhizophoraceae) extinct. The habitat of this species is likely to have been destroyed by operations for oil division of Cross exploration. However, it is reported from Oban division of Cross River National Park River National Park Bulbophyllum filiforme CR This is a species of lowland evergreen forest, where it occurs as an epiphyte. The main Cameroon; Nigeria 50 Kraenzl. (Orchidaceae) threat to the species is forest clearance for agriculture, particularly plantations. Bulbophyllum nigericum VU The Nigerian locations are threatened by continued extensive clearance of forest to high Cameroon; Nigeria 51 Summerh. (Orchidaceae) elevations; one or more of these subpopulations are likely lost. In all, a loss of over 30% of the population is estimated over the past three generations, which we here estimate to be 10 years, much of this loss being irreversible. Calpocalyx cauliflorus VU Known from one outlying population west of the Niger River in Nigeria and otherwise Cameroon, Nigeria 52 Hoyle (Mimosaceae) confined to remaining forest in the east extending into Cameroon. The forest habitat has been extensively felled outside protected areas. Desmostachys vogelii Stapf. VU The species habitat has declined because of mining and logging activities and the Cameroon; Ghana; 53 (Icacinaceae) establishment of commercial plantations. Nigeria Dielsantha galeopsoides EN A population reduction of two-thirds over the next ten years of what is the world’s only Cameroon; 54 (Engl. & Diels) E. Wimm. known extant sites for Dielsantha is thus projected. Threatened by forest clearance for Equatorial Guinea (Syn: Lobelia galeopsoides agriculture: suitable habitat at Bioko was destroyed for cocoa plantations, habitat at Lake (Bioko); Nigeria Engl. & Diels.) Borombi Mbo was reported destroyed in 2002. (Campanulaceae) Dorstenia prorepens Engl. VU Threatened by forest loss due to agricultural and urban expansion. Threats include forest Cameroon; 55 (Moraceae) loss due to agricultural expansion and wood excavation, particularly at Bambuko, and at Equatorial Guinea due to urban expansion at Kumba. (Bioko); Nigeria 113 Herb Tree Tree Shrub Shrub Shrub Tree Epiphyte Epiphyte Tree Tree Herb Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Dombeya ledermannii Engl. CR This species is known from Cameroon (the Bamenda Highlands), and Nigeria (Mambilla Cameroon, Nigeria 56 (Malvaceae) Plateau and Jos Plateau). The main threats to the population are clearance for agriculture and over-exploitation for bast fibre. Disperis mildbraedii Schltr. VU There is continuing decline because of continued clearance of forest on Bioko, in the Cameroon; 57 ex Summerh. (Orchidaceae) Bamenda Highlands and in neighbouring parts of Nigeria. Hence listed as Vulnerable. Equatorial Guinea Attempt to relocate this species and introduce it into cultivation. (Bioko); Nigeria Dracaena viridiflora Engl. VU Despite the relatively large altitudinal range and extent of occurrence of this species, it is Cameroon; 58 & K. Krause (Dracaenaceae) rare throughout, being known from only seven locations. The total area of occupancy is Equatorial Guinea; likely to be less than 2,000 km², and there is continuing decline as the sites in Nigeria Nigeria and the lowland site(s) in S. Province, Cameroon, are under threat from forest clearance for agriculture and logging. Deinbollia insignis Hook f. VU This large treelet, with leaves to 1 m long, is only known from six locations, all of which Native to 59 (Sapindaceae) are threatened with, or have suffered forest clearance. It is suspected that, when better Cameroon, possibly data are available, this species may prove to be Critically Endangered. It may well be extinct in extinct on Bioko due to extensive forest clearance there for Cacao plantations in the late Equatorial Guinea 19th and 20th centuries. It may also be extinct in Nigeria due to extensive forest loss (Bioko); Nigeria there in the late 20th century. Extremely vulnerable due to clearance of lowland forest for agriculture. It may well be extinct on Bioko due to extensive forest clearance there for cacao plantations in the late 19th and 20th centuries. It may also be extinct in Nigeria due to extensive forest loss there in the late 20th century. Forest loss at Bambuko is documented in Cable and Cheek (1998). It is notable that the species was not found elsewhere around Mt Cameroon during the intensive surveys of the early 1990s. At Mt Kupe it is vulnerable due to its low altitude, placing it outside of the proposed new protected area. Deinbollia maxima Gilg. VU The species is declining due to forest clearance for timber and agriculture, particularly in Cameroon; Gabon; 60 (Sapindaceae) Nigeria, Mt Cameroon and the Libreville area. Threats in Sierra Leone are unknown. Nigeria; Sierra Leone Deinbollia saligna Keay VU Populations in unprotected forest have been exposed to extensive logging and clearing Cameroon; Ghana; 61 (Sapindaceae) for agriculture. Occurring in a few localities in Nigeria and Cameroon and is recently Nigeria recorded in Ghana. Drypetes molundana Pax & VU Although fairly widespread and well-collected, most of its known sites (eight out of Cameroon; Nigeria 62 K. Hoffm. (Euphorbiaceae) eleven) have suffered forest clearance over the last three decades. Clearance of forest for wood, agriculture and urban expansion (Kumba and Nkolbisson) is recorded at 8 of the 11 known sites and it has been extensive at many of these. Drypetes obanensis S. VU Endemic to the Oban Division of the Cross River National Park, Nigeria. Pressures from Nigeria: Oban 63 Moore (Euphorbiaceae) commercial logging and agriculture are very strong outside the park. Division, Cross River National Park (Cross River State) Drypetes preussii (Pax) VU Drypetes preussii was treated there as being restricted to Cross River in Nigeria and Cameroon; Gabon; 64 Hutch. (Euphorbiaceae) adjoining forests in Cameroon. Inspection of specimens at the Kew Herbarium shows Nigeria that its range extends along the coast to Gabon. Accordingly its extent of occurrence now 114 Tree Epiphyte shrub Tree Tree Shrub Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 exceeds 20,000 km², so it is re-evaluated here according to the new information. It is considered that eight locations are known and there is continuing decline due to habitat loss. Threats to lowland forest in the Mt Cameroon area are documented in Cable and Cheek (1998) and also see below. Outside of protected areas forest has been comprehensively logged and cleared for agriculture. Drypetes staudtii (Pax) VU Although known from only nine sites there are indications that it is locally fairly Cameroon; Nigeria 65 Hutch. (Euphorbiaceae) common. At Omo there are four collections, and at the Mokoko River F.R. (Mt Cameroon) there are eight. Meanwhile, adjacent forest reserves such as Onge or Bakundu have no records of the taxon. If better data on local threats were available throughout the range of this taxon, it would be better assessed under criterion A and then would be likely to rate as EN or CR. Extensive losses of forest areas have occurred in Nigeria and are ongoing at Wum (M. Cheek pers. obs.). The forest at Mokoko has also been under great pressure for clearance. Clearance of forest for timber and expansion of agriculture, both large-scale commercial and small-holder. Encephalartos barteri VU Encephalartos barteri comprises two subspecies - E. barteri barteri, which is more Benin; Ghana; 66 Carruth. ex Miq. widespread and numerous and has been assessed as Vulnerable, and E. barteri Nigeria; Togo (Zamiaceae) allochrous, which has a restricted distribution and has been assessed as Endangered. The overall assessment of Vulnerable is based on past (60 years) and future (next 30 years) population declines that are estimated to exceed 30% (three generations is 210 years). This species may be affected by too frequent fires which could prevent seedling growth. Plants are also removed from the wild by collectors. Part of the population was lost due to flooding when the Volga dam was built. Duguetia barteri (Benth.) VU It is known to occur from south-west Nigeria to Gabon. Most parts of the range have Cameroon; Gabon; 67 Chatrou (Annonaceae) suffered large-scale declines in its habitat because of logging and the demand for land for Nigeria cultivation. Entandrophragma utile VU An important source of African mahogany. This widespread species is heavily exploited Angola (Angola); 68 (Dawe & Sprague) Sprague throughout its range. Genetic erosion caused by the depletion of mature individuals from Cameroon; Congo; (Meliaceae) subpopulations has taken place in most countries. Local overcutting is also common in Congo, The parts of West Africa. Growth rates are amongst the slowest in the genus and the seeds Democratic and seedlings suffer high mortality rates because of insect attack. Republic of the; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria; Sierra Leone; Uganda Entandrophragma VU A major source of African hardwood. Growth rates are amongst the slowest in the genus. Angola (Angola); 69 cylindricum (Sprague) Exploited heavily throughout its range. Genetic erosion caused by the large-scale Cameroon; Congo; Sprague (Meliaceae) depletion of mature individuals from populations has taken place in some countries. Congo, The Democratic Republic of the; Côte d'Ivoire; 115 Tree Tree Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 70 Entandrophragma candollei Harms (Meliaceae) VU 71 Entandrophragma angolense (Welw.) C. DC. (Meliaceae) VU 72 Eriocaulon asteroids S.M. Phillips (Eriocaulaceae) VU 73 Eriocaulon bamendae S.M. Phillips (Eriocaulaceae) VU 74 Floscopa mannii C.B.Clarke (Commelinaceae) EN CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Gabon; Ghana; Nigeria; Sierra Leone; Togo; Uganda One of the major sources of African mahogany. The species is widespread and heavily Angola (Angola); exploited throughout its range. Cameroon; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Guinea; Liberia; Nigeria One of the main sources of African mahogany. The commercial exploitation of this Angola (Angola); timber species has resulted in the large-scale extraction of mature individuals throughout Cameroon; Central its range. Significant genetic erosion has been reported in some countries. It has the African Republic; potential to occur commonly and regenerates well after logging damage but not after Congo; Congo, The burning. The seed does not appear to disperse over great distances and regeneration is Democratic poor away from parent trees. A slow-growing species. Republic of the; Côte d'Ivoire; Equatorial Guinea (Bioko); Gabon; Ghana; Guinea; Kenya; Liberia; Nigeria; Sierra Leone; Sudan; Tanzania, United Republic of; Uganda Current threats to the species are unknown, however, too much trampling by cattle may Cameroon; Nigeria cause damage to these small annual Eriocaulon plants by dislodging them from the basalt substrate the thin layer of peaty soil in which they grow. Conversely, lack of grazing or of intermittent grassland fires might permit the built-up of enough soil on the pavement to allow a Sporolobus-based community to encroach upon the basalt pavement and smother or compete with the Eriocaulon. The species is vulnerable, above all, to changes to the water table. Drainage of swamps Cameroon; Nigeria or conversely, flooding for use as reservoirs would threaten this species with extinction. The species is also vulnerable to trampling by cattle. This species is probably often overlooked due to its small size and unspectacular nature. Cameroon; Nigeria However, it is nevertheless highly rare in view of the fact that only four collections are known. It would probably be susceptible to complete forest clearance for agriculture, 116 Tree Tree Herb Herb Herb Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 which is occurring across much of its known range. Gossweilerodendron EN This timber species is declining in population numbers. In the main Democratic Republic Angola (Angola); 75 balsamiferum (Verm.) of Congo/Nigeria forest block it is generally rare or absent. Heavy exploitation and Cameroon; Congo; Harms (Caesalpiniaceae) habitat loss. Congo, The Democratic Republic of the; Equatorial Guinea; Gabon; Nigeria Hallea stipulosa (DC.) VU In many places it suffers from over-exploitation. M. Cheek (pers. comm.) reports that is Angola (Angola); 76 Leroy (Rubiaceae) not over-exploited in the Cameroon, but this may be the case elsewhere. Cameroon; Central African Republic; Congo; Congo, The Democratic Republic of the; Gabon; Gambia; Ghana; Guinea; Nigeria; Senegal; Sierra Leone; Sudan; Uganda; Zambia Hallea ledermannii (K. VU Overexploitation of the general-purpose timber and habitat degradation in large parts of Angola (Angola); 77 Krause) B. Verdcourt its range are causing population declines Benin; Cameroon; (Rubiaceae) Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Equatorial Guinea; Gabon; Ghana; Liberia; Nigeria Haplormosia monophylla VU It is expected that overexploitation and habitat degradation are resulting in population Cameroon; Côte 78 (Harms) Harms declines. d'Ivoire; Liberia; (Papilionaceae) Nigeria; Sierra Leone Jollydora glandulosa VU Known from four localities. In Nigeria, it exists only on the Obudu Plateau in Cross Cameroon; Nigeria 79 Schellenb. (Connaraceae) Rivers National Park, where it is confined to forested valleys. In Cameroon, the species is restricted to the west, at sites near Obang, Limbe and Ediki. Damage to the habitat is incurred from frequent fires and also from encroaching agriculture, especially banana plantations but also subsistence farming. Liparis goodyeroides Schltr. CR There has been one collection of this species in Nigeria and three collections in west Cameroon; Nigeria 80 (Orchidaceae) Cameroon, one of which was from Mt. Cameroon. The type collection is from Moliwe and the only other collections known are from south of Ngu at the Plain of Mbaw, 117 Tree Tree Tree Tree Tree Epiphyte Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Takamanda, and the Niger Estuary. Forest clearance for agriculture (particularly plantations) and firewood. Hymenostegia bakeriana VU Confined to the Oban Division of the Cross River National Park and the adjacent Korup Cameroon; Nigeria 81 Hutch. & Dalz. National Park in Cameroon. Large-scale deforestation has taken place in surrounding (Caesalpiniaceae) areas. Hymenostegia talbotii Baker CR A little-known species, which has been recorded only from Eket in south-east Nigeria. Nigeria: Eket 82 f. (Caesalpiniaceae) Oil exploration operations in this area have caused the destruction of most if not all the forest habitat. Loesenera talbotii Baker f. VU In Nigeria this species is known from the Oban Hills, where the population is protected Cameroon; Nigeria 83 (Caesalpiniaceae) within Cross River National Park and Calabar-Mamfe. In SW Cameroon found in Yingui-Yabassi, WSW Mamfe (one collection each), and Mt Kupe-Bakossi (numerous sites and collections). Areas outside protected areas have suffered serious habitat declines due to forest clearance for agriculture and wood, e.g., at Kupe village. Mikaniopsis maitlandii C.D VU Threatened by forest clearance for agriculture and wood, particularly likely at the lower Cameroon; 84 Adams (Asteraceae) part of its altitudinal range at sites such as Chappal Waddi and Mt Cameroon (plantation Equatorial Guinea expansion to the 1,000 m contour is a major threat). (Bioko); Nigeria Monodora unwinii Hutch. & VU A forest tree, endemic to western Nigeria. Only a small area of forest remains and the Nigeria: Unwin 85 Dalz. (Annonaceae) extent of it continues to decline because of logging pressures and the demand for land for (Edo State) commercial crops and subsistence farming. Neolemonniera EN Much of its habitat has been lost to agriculture, mining and logging. Population numbers Ghana; Liberia; 86 clitandrifolia (A.Chev.) have been observed to decline rapidly. Nigeria; Sierra Heine (Sapotaceae) Leone Nesogordonia papaverifera VU Genetic impoverishment is reported in outlying parts of the species' range. Exploitation Benin; Cameroon; 87 (A. Chev.) Capuron is moderate. Sometimes large individuals are left after logging. Central African (Sterculiaceae) Republic; Congo; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria; Sierra Leone Nodonema lineatum VU Removal of shade due to forest clearance is the most likely threat. The rock face habitat Cameroon; Nigeria 88 B.L.Burtt (Gesneriaceae) itself is not likely to be mined, but plants are vulnerable to rock falls. Much forest clearance in Ogoja has occurred in recent decades. Removal of shade due to forest clearance is the most likely threat. The rock face habitat itself is not likely to be mined but plants are vulnerable to rock falls. Much forest clearance in Ogoja has occurred in recent decades. Napoleonaea egertonii VU This striking forest tree was known from very few sites prior to the plant inventory work Cameroon; Gabon; 89 Baker f. (Lecythidaceae) in western Cameroon beginning in the 1980s. Discoveries of this species at Takamanda Nigeria and Korup are important as it is relatively well protected at these sites; however, it is not common at Korup, only 1–2 trees having been found (M. Cheek pers. obs.), and its abundance at Takamanda is unknown. At Kupe Village and the adjacent Manehas Forest Reserve, the species is again uncommon, one plant being found at each location. 118 Tree Tree Tree Tree Tree Tree Tree Herb Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 However, several specimens were observed within close proximity to Nyandong in W. Bakossi. The Nigerian locations are likely to have been either lost or under severe threat from widespread logging of lowland forest here. The two sites at Mt Kupe are below the 1,000 m lower limit of effective forest protection and thus vulnerable to agricultural encroachment. At Nyandong, several trees were recorded close to the village and adjacent to tracks; these are highly vulnerable to future expansion of the village and road improvement. Napoleonaea lutea Baker f. CR This species, along with N. reptans, is poorly documented and apparently confined to Nigeria: Eket 90 ex Hutch. & Dalz. Eket in south-east Nigeria. Oil exploration operations in the area are causing extensive (Lecythidaceae) damage, to the habitat, if not its complete destruction. Napoleonaea reptans Baker CR This species, along with N. lutea, is poorly documented and confined to the Eket area in Nigeria: Eket 91 f. ex Hutch. & Dalz. south-east Nigeria. Oil exploration operations are causing extensive damage, if not (Lecythidaceae) complete destruction of the habitat. Nothospondias staudtii Engl. VU Semi-deciduous forest has been heavily logged everywhere. Cameroon; Côte 92 (Simaroubaceae) d'Ivoire; Gabon; Ghana; Nigeria Vepris lecomteana (Pierre) VU This monopodial tree though fairly widespread and conspicuous, is rare (less than 10 Cameroon; Gabon; 93 Cheek (Syn: Oricia locations are known) and declining due to clearance of lowland forest for agriculture and Nigeria lecomteana Cheek) wood. Threatened by clearance of lowland forest for agriculture and wood, particularly (Rutaceae) in the Mt Cameroon area (Cable and Cheek 1998) and in Nigeria. Pentas ledermannii Krause VU Frequent, human-set fires in grasslands in these same areas probably also adversely Cameroon; Nigeria 94 (Rubiaceae) affect the grassland-forest interface as a habitat for this taxon, although occasional natural fires may aid its regeneration. Pseudagrostistachys VU There is continuing decline because of forest clearance for wood and agriculture in parts Cameroon; 95 africana (Müll.Arg.) Pax & of its range. On the Obudu Plateau fires and encroaching agriculture are causing damage Equatorial Guinea K.Hoffm. (Euphorbiaceae) to the restricted areas of remaining vegetation in forested valleys. General threats from (Bioko); Ghana; mining, logging and commercial forestry can affect these areas. Nigeria; Sao Tomé and Principe (Sâo Tomé) Pteleopsis habeensis EN In Ghana the establishment of a plantation and the influx of people into the area have Ghana; Mali; 96 Aubrev. ex Keay caused declines in the species' habitat. Nigeria (Combretaceae) Pterygota bequaertii De VU The species appears to be suffering declines because of levels of exploitation through Cameroon; Congo, 97 Wild. (Sterculiaceae) most of its range. The Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Nigeria Pterygota macrocarpa K. VU Exploitation for the timber occurs at high levels throughout its range and is likely to be Cameroon; Côte 98 Schum. (Sterculiaceae) causing population declines. d'Ivoire; Ghana; Nigeria; Sierra 119 Tree Tree Tree Tree Herb Tree Shrub Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 99 Pseudosabicea pedicellata (Wernham) N.Hallé (Rubiaceae) VU 100 Pseuderanthemum dispersum Milne-Redh. (Acanthaceae) VU 101 Polystachya cooperi Summerh. (Orchidaceae) EN 102 Piptostigma giganteum Hutch. & Dalz. (Annonaceae) VU 103 Pararistolochia goldieana (Hook.f.) Hutch. & Dalz. (Aristolochiaceae) VU 104 Quassia sanguinea Cheek & Jongkind ined. (Simaroubaceae) VU 105 Raphia regalis Becc. (Arecaeae) VU CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Leone Cameroon; Nigeria A scandent shrub apparently more common in S.E. Nigeria than adjoining Cameroon, this species grows in a particularly threatened habitat. Only seven locations are known. Declining due to clearance of forest for agriculture and wood; this has been particularly prevalent in Nigeria in recent decades, although several collection sites of this species are from protected areas. However, those in Cameroon appear to be unprotected. This robust herb or shrub appears rare throughout its range, and was recorded only once during the extensive inventory work in S.W. Province, Cameroon, during the 1980s and 1990s, a collection by D.W. Thomas at Bangem in north Bakossi. A continued decline in habitat is inferred by clearance of extensive areas of lowland and mid-elevation forest throughout its range for plantation agriculture and timber. There is continuing decline because of extensive and continued forest clearance at high latitudes in eastern Nigeria and at Muanenguba in Cameroon. Extensive and continued forest clearance at high latitudes in E Nigeria and at Mwanenguba threaten any remaining populations at these sites. This species appears to be known only from the Oban Division of the Cross River National Park. Unprotected forest has been extensively logged and cleared for cultivation. Although widespread, it is rare. Despite intensive surveys over several years at Mt Cameroon, only a single individual was found (Cable and Cheek 1998). Forest loss has been extensive throughout Sierra Leone and Nigeria and is continuing; it is unlikely that this plant survives at its Calabar or Lagos localities, for example. Threatened by clearance of forest for timber and agriculture. By extrapolation, it is estimated that over 30% of the overall population has been lost due to habitat destruction over the last three generations, or sixty years (estimating one generation at twenty years). Threatened by forest clearance for wood, followed by agriculture, particularly in the northern part of its range, Bamboutos Mts and the Bamenda Highlands. First described from a 1910 collection from the Oban area, Nigeria, this species was thought extinct in that country until a conscious effort to rediscover it in the 1970s by Otedoh proved successful, it being recorded in large numbers (at that time) in the Equi Issu hills near the Cameroonian border. This highly distinctive palm, with no aerial trunk and with leaves rating amongst the largest in the plant kingdom, is likely under-recorded due to difficulties in collecting specimens of it, and in the fact that it has received limited taxonomic attention, being treated only briefly in Otedoh’s revision of the genus Raphia (Journal of the Nigerian Institute for Oil Palm Research 6(22), 1982), with no specimen citations. Continuing decline is inferred because of extensive forest clearance for timber and for agricultural expansion in Nigeria and Bakossi. Selective felling for use in building and tapping of palm wine, mainly in Nigeria, poses a serious threat. The species may well be more threatened than the current listing indicates. 120 Shrub Cameroon; Nigeria Herb Cameroon; Nigeria Epiphyte Nigeria: Oban Division, Cross River National Park (Cross River State) Cameroon; Equatorial Guinea (Bioko); Nigeria; Sierra Leone Tree Cameroon; Nigeria Tree Angola (Angola, Cabinda); Cameroon; Congo; Gabon; Nigeria Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Rhabdotosperma VU This species is known from eight locations and is declining due to deforestation for Cameroon; Nigeria 106 ledermannii (Murb.) Hartl. agriculture. It is estimated that there has been This equates with about a 30% loss in area (Scrophulariaceae) of occupancy for this species over the last 10 years. Loss of montane forest due to agriculture is thought to be the main concern for this species. 25% of forest cover was lost in a sample area of the Bamenda Highlands between 1987 and 1995 (Moat in Cheek et al. 2000). Rhodognaphalon brevicuspe VU A timber species of West and Central Africa. Exploitation is moderate. Little is known Cameroon; Congo; 107 (Sprague) Roberty about regeneration but it does not appear to be abundant and growth rates are slow. Congo, The (Bombacaceae) Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Nigeria; Sierra Leone Robynsia glabrata Hutch. VU These areas are vulnerable to the effects of population growth and associated activities. Côte d'Ivoire; 108 (Rubiaceae) The species is uncommon. Ghana; Nigeria Rutidea nigerica Bridson VU Although it has a fairly wide distribution, this liana is known from only ten localities, at Benin; Cameroon; 109 (Rubiaceae) some of which (e.g., Lagos, Kumba) it may very well already be extinct due to forest Nigeria clearance for agriculture and wood. Threatened by forest clearance for agriculture and wood; it is very likely that its habitat has been lost at Lagos and Kumba where there has been extensive forest clearance in recent decades’ as there has been in much of Nigeria. Surveys should be made to attempt to rediscover this species at its known sites, and to evaluate the size of subpopulations, regeneration, local threats and possibilities for conservation. Sabicea xanthotricha VU This species is currently only known from four locations and is very likely to be Cameroon; Nigeria 110 Wernham (Rubiaceae) declining due to forest clearance for agriculture and wood. Threatened by forest clearance for agriculture and wood, particularly at Oban and at Mokoko F.R. Soyauxia talbotii Baker f. EN A small tree which is recorded only in south-east Nigeria. The family is endemic to West Nigeria: Eket 111 (Medusandraceae) Africa. Unprotected forest has been extensively logged and cleared for cultivation. Saxicolella marginalis CR This species has only been recorded from Nigeria and Cameroon. There is a continuing Cameroon; Nigeria 112 (G.Taylor) C. Cusset ex decline of its habitat quality due to water pollution and its populations are severely Cheek (Podostemaceae) fragmented. The species may also be present in Ghana and Niger but this needs to be confirmed. It is therefore listed as Critically Endangered. Drought and water pollution have been identified as major threats. The species may be threatened by pollution from laundry operations at the town of Fundong, Cameroon just upstream from the waterfall. Also, a lot of debris has been seen at the side of this pool. Scaphopetalum parvifolium VU This small forest tree is recorded from the Oban Hills, within Cross River National Park. Nigeria: Oban 113 Baker f. (Sterculiaceae) Unprotected forest has been extensively logged and cleared for cultivation. Division, Cross River National Park (Cross River State) 121 Herb Tree Tree Liana Tree Tree Herb Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 Vitellaria paradoxa VU This species has been overexploited for timber, firewood and charcoal production. Its 114 C.F.Gaertn. (Sapotaceae) habitat is also suffering from agricultural encroachment and increasing population pressure. 115 Talbotiella eketensis Baker f. (Caesalpiniaceae) EN 116 Tapinanthus preussii (Engl.) Tiegh. (Loranthaceae) VU 117 Tieghemella heckelii (A.Chev) Pierre ex Dubard (Sapotaceae) EN 118 Trichoscypha mannii Hook.f. (Anacardiaceae) VU 119 Trichostachys interrupta K. Schum. (Rubiaceae) VU 120 Turraeanthus africanus (Welw.) Pellegr. (Meliaceae) VU ISSN: 2277-1948 Cameroon; Congo, The Democratic Republic of the; Côte d'Ivoire; Ghana; Guinea; Nigeria; Senegal; Sudan; Uganda Found only in south-east Nigeria. In Eket the habitat appears to have been almost completely destroyed because of oil exploration operations. Elsewhere levels of logging and clearing are high outside protected areas. This parasitic shrub is known from only 11 localities in lowland forest (Polhill and Wiens 1998). It appears to have a very patchy distribution, not being recorded from some extensive areas which have been well surveyed, such as Mt Cameroon (Cable and Cheek 1998). The low altitude at which it occurs makes it vulnerable to forest clearance throughout its range. Threatened by clearance of forest for agriculture and wood. There are only two species in the genus. An important timber species found mainly in wet evergreen rainforest. Overexploitation in some countries is leading to serious population declines, notably in Ghana and in Liberia, where there is a possibility of the species becoming extinct. Regeneration may also be limited in parts of its range because of the reduction in elephant numbers and other seed dispersers. Needs to be reassessed as the species now includes T. atropurpurea (was previously also listed as Vulnerable) and thus has a much wider distribution than originally thought. Unprotected forests have been heavily logged and cleared for commercial and subsistence agriculture. Mining, logging and the establishment of industrial plantations have also caused decline in parts of Upper Guinea. There is a protected subpopulation in the Oban Hills, in Cross River National Park, Nigeria. Known from six locations and declining due to clearance of forest for agriculture. This clearance has occurred extensively in Nigeria, and at Barombi Mbo in Cameroon, where the species may no longer occur. A monotypic genus endemic to the Guineo-Congolian regional center of endemism. It is exploited at moderate levels for its timber and is becoming rare in places. 122 Tree Nigeria: Eket, Degema Shrub Angola (Angola, Cabinda); Cameroon; Gabon; Nigeria Shrub Cameroon; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria; Sierra Leone Cameroon; Côte d'Ivoire; Ghana; Liberia; Nigeria Tree Cameroon; Nigeria Shrub Angola (Angola); Benin; Cameroon; Congo, The Democratic Republic of the; Côte d'Ivoire; Equatorial Guinea; Ghana; Nigeria; Sierra Leone; Uganda Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Tricalysia talbotii VU Known from only ten locations and declining due to clearance of forest for agriculture Cameroon; Nigeria 121 (Wernham) Keay and wood. Given the far-reaching forest loss in Nigeria and anticipated increased forest (Rubiaceae) loss along the upgraded Kumba-Mamfe Road, the prospects for this species do not seem good. Reassessment is likely to result in an EN or CR rating. Threatened by clearance of forest for agriculture and wood. Uvariastrum zenkeri Engl. & VU This species has been recorded only in south-east Nigeria and neighbouring Cameroon. Cameroon; Nigeria 122 Diels (Annonaceae) Unprotected forests have been heavily logged and cleared for commercial and subsistence agriculture. Warneckea memecyloides VU The range of this forest type is restricted and has declined because of mining, logging Cameroon; Côte 123 (Benth.) H.Jacques-Felix and other commercial forestry activities in all areas. Although much forest remains in d'Ivoire; Gabon; (Melastomataceae) Gabon, it is now largely under concession to logging companies. Ghana; Nigeria Afzelia pachyloba Harms VU Heavily exploited for its commercial timber. Relatively few seed trees remain throughout Angola (Angola); 124 (Caesalpiniaceae) its range. Cameroon; Congo; Congo, The Democratic Republic of the; Gabon; Nigeria Eribroma oblonga (Mast.) VU Levels of exploitation for its timber are moderate and are contributing to the declines in Cameroon; Côte 125 Pierre ex A.Chev. population numbers. d'Ivoire; Equatorial (Sterculiaceae) Guinea (Bioko); Gabon; Ghana; Liberia; Nigeria; Sierra Leone Uvariopsis tripetala (Bak.f.) VU A small tree found in dry forest. Its habitat is most vulnerable to agricultural expansion Ghana; Nigeria 126 G.E. Schatz (Syn: Dennettia and the effects of high population growth and fires. tripetala Bak.f.) (Annonaceae) Vernonia bamendae C. D. VU Known from Cameroon (Bamenda Highlands), and Nigeria (Mambilla Plateau). It is Cameroon; Nigeria 127 Adams (Asteraceae) curious that despite collecting expeditions in 1996, 1998 and 1999, this species has not been rediscovered from its type locality. It may be that it is not only narrowly endemic, but within its small range, extremely rare and possibly declining. The current threats to this species are unknown, but the incidence of grazing and fire are likely to be important factors in the survival of this species. Uvariodendron occidentale VU Dry forests have been heavily degraded and lost to agricultural expansion, overgrazing, Cameroon; Côte 128 Le Thomas (Annonaceae) fire and in some cases the introduction of invasive species such as the neem tree. d'Ivoire; Ghana; Liberia; Nigeria Xylopia africana (Benth.) VU Presumably this species was once common in the Bamenda Highlands where it is now all Cameroon; Nigeria; 129 Oliv. (Annonaceae) but extinct. While there are no figures for rates of forest loss in the Bamenda Highlands Sao Tomé and as a whole, in one area which has been studied, the Kilum-Ijim area, forest loss of 25% Principe (Sâo over 8 years in the 1980s–1990s has been recorded (Moat in Cheek et al. 2000). Past Tomé) forest loss in the Bamenda Highlands is therefore the main basis for the listing ofXylopia 123 Tree Tree Tree Tree Tree Tree Shrub Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 africana. On Mt Cameroon it appears rare, being found only twice in the surveys of 1992–1994. Elsewhere in the mountains of the Cameroon line it is also known from the extension into Nigeria: the Obudu Plateau where it is also threatened due to forest clearance, if indeed, it is still extant there. It is also known from São Tomé in the Gulf of Guinea. Strangely, it is not known from Bioko, nor from the Rumpi Hills nor the Bamboutos Mts, Mt Kupe and the Bakossi Mts are now probably the largest single subpopulation of Xylopia africana. Clearance of forest for timber and agricultural land. Xylopia talbotii Exell VU Subpopulations of this forest tree were known in Eket and Oban. The Eket subpopulation Nigeria: Oban 130 (Annonaceae) is likely to have been seriously or completely destroyed by oil exploration operations. Division, Cross Oban population is relatively well protected within the 3,000 km² of the southern River National Park division of the Cross River National Park. (Cross River State); Eket (Akwa Ibom State). Justicia camerunensis VU In Cameroon it has a patchy distribution, being absent from several seemingly suitable Cameroon; Nigeria 131 (Heine) B.J.Pollard areas including the Bakossi Mountains and much of Mt Cameroon. Throughout its range, (Acanthaceae) it is threatened by extensive forest clearance, and many subpopulations have already disappeared. Throughout its range, it is threatened by extensive forest clearance. The Northwest Province subpopulation is highly threatened as closed-canopy forest is scarce here today; it was noted in the collection of 1975 that the forest patch in which it was found was "now in exploitation by local people with handsaws"; this site is therefore likely to be lost. At Mt Kupe, it was recorded most often above Nyasoso, at around 1,000 m alt., where agricultural encroachment is causing significant losses of forest. Sites around Yaoundé are also likely to have been lost. Justicia orbicularis (Lindau) VU A highly distinctive species known from just 12 locations. Populations appear disjunct, Cameroon; Nigeria 132 V.A.W.Graham being absent in several seemingly suitable areas. In Bakossi, it is only known in the west, (Acanthaceae) though further exploration of the lowlands of southern Bakossi may reveal further populations. It is also absent from the lowlands around Mt Cameroon, and has not been recorded in extensively collected forest areas around Bipinde and Kribi in South Province, Cameroon. Throughout its range, deforestation has been extensive in the lowlands, and this continues outside protected areas. Ixora degemensis Hutch. & EN A shrubby tree endemic, confined to an area on the coast at Degema. Nigeria: Degema 133 Dalz. (Rubiaceae) Ixora foliosa Hiern VU About half the area where this characteristic tree of wet montane forest occurred was in Cameroon; Nigeria 134 (Rubiaceae) the Bamenda Highlands. They are now destitute of natural forest except for a very few exceptions. It is estimated that over 30% of the habitat of this tree has been lost over the last century and that over 30% of that remaining will be lost in the next century. Threatened by forest clearance for agriculture and wood, especially in the Bamenda Highlands, once probably the main area for this species. In one study area of these highlands, 25% of forest was lost between 1987 and 1995 (Moat in Cheek et al. 2000). Ixora nigerica Keay VU This shrubby tree is endemic to southern Nigeria. Nigeria: Ndealichi 135 (Rubiaceae) FR, Ukpon FR 124 Tree Tree Shrub Tree Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 136 Begonia preussii Warb. (Begoniaceae) VU 137 Begonia pseudoviola Gilg. (Begoniaceae) VU 138 Begonia schaeferi Engl. (Begoniaceae) VU 139 Diospyros crassiflora Hiern. (Ebenaceae) EN 140 Diospyros barteri Hiern. (Syn: Diospyros hirta Gürke ex Hutch. & Dalziel) (Ebenaceae) Eugenia gilgii Engl. & Brehmer (Myrtaceae) VU 142 Guarea cedrata (A. Chev.) Pellegrin (Meliaceae) VU 143 Guarea thompsonii Sprague & Hutch. (Meliaceae) VU 141 CR CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 (Cross River State) Clearance of forest for wood and agricultural land (especially plantations) is a major Cameroon; threat throughout its range and probably accounts for the lack of collections from Bioko Equatorial Guinea in the last century (where forest was largely cleared below 1,000 m alt.). (Bioko); Nigeria The prognosis for habitat destruction for this taxon is high. This taxon might be better Cameroon; Nigeria assessed, but lack of data on the state of sites west of the Bamboutos Mts makes this difficult to apply. Threatened by forest clearance for wood and agriculture. The assessment of this species as VU in Cheek et al. (2000) is maintained here as no new Cameroon; Nigeria data are available on the taxon. The species is known from collections made from Obudu Plateau in Nigeria, and Manenguba, Mt Nlonako, Bamboutos Mts, Bamenda Highlands, and the Kongoa Mountains, Cameroon. While cliff faces generally are unlikely to be disturbed, clearance of adjoining forest for fuel and agriculture could endanger this species by removing the shade necessary for its survival. Virtually all large trees of this species have been felled for the ebony wood, except Cameroon; Central perhaps in the most remote parts of its range. African Republic; Congo; Congo, The Democratic Republic of the; Gabon; Nigeria General forest loss has been high in all three countries where it is found because of Cameroon; Ghana; logging, mining, oil exploration and commercial forestry activities. Nigeria The natural habitat of this species has been almost completely destroyed and the remaining area is disappearing rapidly. Recorded from Cameroon (the Bamboutos Mountains, Bamenda highlands, and Ngaoundere), and Nigeria (Mambilla Plateau). The largest subpopulation is estimated at about 50 trees (at Mbingo). The clearance of forest areas for wood and agricultural land forms the main threat to the survival of this species. Levels of exploitation are moderate and the species often suffers from its similarity to Entandrophragma angolense, resulting in it being harvested with the same intensity. Although moderately exploited, this species is less commercially important than G. cedrata. Growth is slow, reaching only 9 ft (DBH) in 200 years. 125 Herb Herb Herb Tree Tree Cameroon; Nigeria Tree Cameroon; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Ghana; Liberia; Nigeria; Sierra Leone; Uganda Cameroon; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Gabon; Ghana; Liberia; Nigeria Benin; Nigeria Homalium dalzielii Hutch. (Flacourtiaceae) Cola nigerica Brenan & Keay (Sterculiaceae) VU A small tree recorded in Lagos in Nigeria and from Dja and Kpoguidi in Benin. CR 146 Cola hypochrysea K. Schum. (Sterculiaceae) VU 147 Cola glabra Brenan & Keay (Sterculiaceae) VU 148 Macaranga paxii Prain (Euphorbiaceae) VU 149 Memecylon candidum Gilg. (Melastomataceae) Millettia macrophylla Benth. (Papilionaceae) VU 151 Millettia conraui Harms. (Papilionaceae) VU 152 Schefflera mannii (Hook.f.) Harms (Araliaceae) VU 153 Terminalia ivorensis A. Chev. (Combretaceae) VU Collected from Mt. Cameroon (one pre-1988 collection) and Nigeria (ca. five collections). Cola nigerica is extremely rare in each of the five disjunct areas in its range. For example in the 1992 survey of Mabeta-Moliwe, while 22 specimens of Cola flavo-velutina were recorded, only a single specimen of Cola nigerica was found. All the areas in which Cola nigerica occurred have been cleared or are under threat of forest clearance and cultivation. Its range extends from south-eastern Nigeria, (although it does not appear to occur in Cross River National Park), to Cameroon, where it has been recorded from Japoma, Dibamba, Eseka, Kribi, Ebolowa and Campo. Unprotected areas have been extensively logged and cleared for agriculture. A small tree confined to the few remaining forested areas in south-west Nigeria. Largescale logging, encroaching agriculture and the planting of commercial crops have resulted in large declines in the habitat. Extending from south-eastern Nigeria to Cameroon. There is a subpopulation in the Oban Division of the Cross River National Park in Nigeria and in Cameroon the species is recorded in Ebone, Mantoum and Mt. Cameroon. Unprotected forests have been heavily logged and cleared for agriculture. Confined to an area extending from south-east Nigeria to Cameroon. Outside protected areas deforestation has occurred on a large scale. A small forest tree which occurs in areas of remaining forest, ranging from south-east Nigeria to Cameroon. Also recorded from Bioko (Equatorial Guinea). There are only eight collections in the Kew Herbarium from Cameroon. Unprotected forest has been heavily logged and cleared for agriculture. A small forest tree, similar to M. macrophylla, with a range extending from south-east Nigeria into Cameroon. Unprotected forest has been heavily logged and cleared for agriculture. Forest clearance for agriculture and wood has reduced the habitat of this species by an estimated 30% or more over its whole range due principally to loss in the Bamenda Highlands, which, having the largest area above 2000 m in the Cameroon uplands, was probably once the stronghold for this species. Between 1987 and 1995, 25% of forest was lost in one area of the Bamenda Highlands (Moat in Cheek et al. 2000). Extensive losses of habitat have also occurred at Manenguba, Obudu, Bamboutos and BafutNgemba. Forest clearance for agriculture and wood are the main threats. Exploitation is moderate. Poor regeneration is often attributed to crop failure. Attempts at plantation growth have generally failed through frequent diebacks. 144 145 150 VU 126 Tree Nigeria; possibly extinct in Cameroon Tree Cameroon; Nigeria Tree Nigeria: Akure FR, Owena FR (Ondo State) Cameroon; Nigeria Tree Cameroon; Nigeria Tree Cameroon; Equatorial Guinea (Bioko); Nigeria Tree Cameroon; Nigeria Tree Cameroon; Equatorial Guinea (Annobón, Bioko); Nigeria; Sao Tomé and Principe (Sâo Tomé) Tree Cameroon; Côte d'Ivoire; Ghana; Guinea; Liberia; Nigeria; Sierra Tree Tree Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences 154 Psychotria podocarpa Petit (Rubiaceae) VU 155 Psychotria moseskemei Cheek (Rubiaceae) CR 156 Prunus africana (Hook f.) Kalkman (Rosaceae) VU 157 Wahlenbergia ramosissima ssp. ramosissim a (Campanulaceae) VU CRDEEP Journals Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Leone A total of six locations are known, where site observations have been made, it is known Cameroon; Nigeria to occupy only 1–2 m². Declining because of clearance for agriculture, especially in the Mt Cameroon area. Threatened by clearance for agriculture especially in the Mt Cameroon area, where the planned expansion of plantations is likely to destroy the subpopulations listed above. A Shrub, rarely a small tree, 2–5 m tall. This newly described montane species has been Cameroon; Nigeria listed as Critically Endangered on the basis that it grows in the same habitat and has a similar range to Chassalia laikomensis. Habitat loss/degradation due to the clearance of land for small-holder farming. Harvesting of bark for the European medicinal market. On Mt Cameroon as with some Angola (Angola); other areas within the range of this species, many trees have died as a result of girdling Burundi; caused by bark removal. The bark from the trees on Mt Cameroon is transported to the Cameroon; Congo, Plantecam factory at Mutengene where it is extracted to produce a powder for export to a The Democratic company in France In recent times; the species was located in Ngel Nyaki Forest Republic of the; Reserve, Mambilla Plateau (Chapman and Chapman 2001). Equatorial Guinea (Bioko); Ethiopia; Kenya; Lesotho; Madagascar; Mozambique; Rwanda; Sao Tomé and Principe (Sâo Tomé); South Africa (Eastern Cape Province, Gauteng, KwaZuluNatal, Limpopo Province, Mpumalanga); Sudan; Swaziland; Tanzania, United Republic of; Uganda; Zambia; Zimbabwe; Nigeria This species is known from only nine specimens at five mountain sites along the Cameroon, Nigeria Cameroon border. It has previously been assessed (Cable and Cheek 1998, Cheek et al. 2000) as Vulnerable. This rating is maintained here because of the small area of occupancy, the number of locations and presumed continuing decline due to the impacts of trampling by cattle during the wet (growing) season. Unknown, but possibly trampling by cattle during the wet (growing) season. It has been reported in Nigeria at Ngel Nyaki Forest Reserve and possibly other parts of Mambilla plateau. 127 Shrub Tree Tree Herb Online version available at: www.crdeep.com SJIF IMPACT FACTOR (2013): 4.183 CRDEEP Journals International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Polygala VU Reported to be native to Cameroon, this species was also discovered in Ngel Nyaki Cameroon, Nigeria 158 tenuicaulis ssp. tenuicaulis Forest Reserve. This subspecies may require fire for regeneration. (Polygalaceae) Stachys VU Current threats to the population are unknown, but may include trampling by cattle. Cameroon; Nigeria 159 pseudohumifusa ssp. saxeri More data is needed on the numbers of individuals at each site, and on the type and level (Lamiaceae) of regeneration. Garcinia kola Heckel VU It is probably the most important source of chewsticks. Overexploitation has caused Benin; Cameroon; 160 (Clusiaceae) population declines. Seedlings are uncommon and slow-growing. Congo, The Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Liberia; Sierra Leone Mansonia EN It occurs particularly in disturbed areas or light gaps in lowland moist forest. Benin; Cameroon; 161 altissima var. Altissima Regeneration is good after disturbance. Congo; Côte (Sterculiaceae) d'Ivoire; Ghana; Nigeria Nauclea diderrichii (De VU It is heavily exploited for its timber, which is used in general construction work. Angola (Angola); 162 Wild. & T.Durand) Merrill Regeneration is good in large canopy gaps but the species is out-competed by other Cameroon; Central (Rubiaceae) pioneers after clear-felling. African Republic; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Gabon; Ghana; Liberia; Nigeria; Sierra Leone; Uganda Synsepalum glycydora VU A small tree, apparently confined to the Oban Hills in Cross River National Park. Nigeria: Oban 163 Wernham (Sapotaceae) Surrounding areas have been extensively logged and cleared for cultivation. However, Division, Cross one doubts if S. glycydora is synonymous to S. dulcificum, because the latter is found in River National Park dry forest areas of Western Nigeria. (Cross River State); Degema (Rivers State). Eriocoelum pungens var. EN The habitat of the Eket subpopulation has been degraded, if not completely destroyed, by Nigeria: Eket and 164 inermis Keay (Sapindaceae) oil exploration operations. The other subpopulation is unprotected and its habitat is Degema vulnerable to severe degradation. Source: IUCN (2012, 2013) 128 Herb Herb Tree Tree Tree Tree Tree Online version available at: www.crdeep.com CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 Discussion A total of 164 threatened species were found in Nigeria, of which 21 were endemic to the country. One of the most important factors considered in the evaluation of a species’ conservation status is species distribution range/endemism (IUCN, 2004). Eket is the home to 10 of the 21 endemic threatened species in Nigeria. This is a big town in Akwa Ibom state in the Southern region of Nigeria, which is also known for its high deposit of crude oil. This attracts the oil exploration activities, which has been noted as a huge threat to the sustainability of the threatened and endemic plants in the region. Furthermore, huge gas flaring and oil exploration was reported to cause acid rain (Nduka et al. 2008). Of the 21 threatened endemic plants reported in this study, 8 were found in the Oban Division of the Cross River National Park. Cross River National Park is the peak of Nigeria’s biodiversity, being the largest tract of the remaining and surviving primary rainforest in Nigeria. About 78% of primate diversity finds home in the National Park; while it harbours another 30 species of non-primate mammals (Stuart et al. 1990). Over 30% of the Nigeria’s 860 bird species are found in the Park (Manu & Imong 2006), while Eniang and Ijeomah (2011) reported 56 species of snake in the Oban division of the Cross River National Park. Larsen (1997) estimated about 950 butterfly species in the Oban division, of which the Cross River National Park officials reported that 2 are endemic and another 2 – Tetrahanis okwangwo and T. oboti are new to science. Furthermore, the Park officials reported that 2 new frog species were identified in the Park, while the floral diversity of the National Park was reported to be 1568 species from 523 genera in 98 families. These include 1303 flowering plants, 141 lichens and 56 moss species. Rubiaceae has the highest number of species representatives among the threatened plant species in Nigeria. Rubiaceae was reported to be among the most diversified and largest of the families in the African rain forest (Robbercht 1996), and the family is identified as the fourth largest plant family globally, with 13,143 species, classiﬁed into 611 genera (Davis et al. 2009), more than 40 tribes, and three subfamilies (Goevarts et al. 2006). They occur on all continents (Goevarts et al. 2006), but most taxa are in tropical or subtropical areas (Bremer & Eriksson 2009). Endemism was reported to be generally high in Rubiaceae because many of the species have restricted distributions (Goevarts et al. 2006). Sixteen (16) of the 164 threatened species in Nigeria were evaluated as “critically endangered”. Under the IUCN, this indicates that there has been a population size reduction by 80 – 90 % in the last 10 years or 3 generations; decline in the area of occupancy of the species; distribution range of less than 10 – 100 km2; extreme habitat destruction, and/or population size estimated as less than 250 mature individuals (IUCN, 2001). Species found in this category are at the highest risk of going extinct, and therefore, there is the need to take strong efforts to conserve the remaining populations. The same goes for the remaining 16 “endangered” and 132 “vulnerable” plants reported for Nigeria. As at January 2010, the IUCN identified 1701 critically endangered species in the Plant Kingdom (IUCN, 2009). However, Butchart et al. (2006) reported that some species may be placed in the critically endangered category because there was no adequate data to support that the species is actually extinct. The documented number of threatened species and extinctions is only the tip of the iceberg, as this number depends on the overall number of assessed species; in addition 5,570 species classified as Data Deficient are possibly threatened (Hilton-Taylor et al. 2008). In another study to compile the endemic flora of Nigeria, 73 of the entire 165 endemic plants were found in Oban Division of the Cross River National Park, while 21 were located in Eket. Furthermore, Rubiaceae ha the highest number of species representatives (16) among the endemic flora recorded in Nigeria. The plant species that have been evaluated in Nigeria is skewed in favor of trees, more than shrubs, herbs and other plant forms. This is probably because trees face more threats than other plant forms, in terms of exploitation for fuelwood, timber, medicinal purposes; and in the forest ecosystems, trees are more or less the keystone species, which other plants and animals rely on for survival. However, there is the need to focus attention also on the shrubs and herbs, especially the one that have high medicinal values, as they are being exploited heavily and harvested unsustainably. A wide range of threats were noted for the threatened plants in Nigeria. Majority of the species found in protected areas were noted to be in high risk due to illegal land use change to agriculture, while those found outside the protected areas are faced with heavy uncontrolled exploitation for timber, fuelwood, chewing sticks and others, wildfire, dam construction, habitat destruction, mining, urban expansion, cattle trampling and grazing, land clearing for farming and oil exploration (Table 1). While the Cross River National Park was reported to be well managed and fully protected; surrounding forests, which ought to serve as buffer zones, were reportedly being heavily exploited for timber and agricultural activities. However, in addition to the anthropogenic threats, there are also biological phenomena noted as threats. These include invasive species, poor/slow growth of the seedlings, genetic erosion, endemism, poor seed viability, die-backs and reduction in seed disperser population, among other biological threats. Indigenous trees in Nigeria have been reported to have long gestation period, slow growth rates of between 1.5m3/ha/year to 2.5m3/ha/year at juvenile stages, irregular fruiting within species of the same type and among species of different types, low variability rates of seeds, low seed production among majority of trees, few species population in a unit area of land, low success rate of regeneration and low coppicing abilities (Oseomobo, 1993), which has impeded the commercial production of most of the indigenous tree species. A good example is Garcinia kola, which is categorised as “vulnerable” for its over-exploitation for chewing sticks in 129 Online version available at: www.crdeep.com CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 most parts of West Africa (Irvine, 1961; Olabanji et al., 1996), but was reported to have very long gestation period to flowering and fruiting (Adebisi, 2004). Lots of these threatened tree species are also subjected to unsustainable debarking for medicinal purposes. One of such is Prunus africana, whose bark is being exploited heavily for international trade to Europe for the treatment of benign prostatic hyperplasia from all the African countries within its distribution range. Overseas trade in P. africana barks from Africa is worth US$220 million/year (Cunningham et al., 1997), while annual export from Cameroon alone was 2000 tonnes/year, worth 1.3 million euros (Nsawir and Ingram, 2007). This species is found in Nigeria only in the Mambilla Plateau, reported in Gashaka Gumti National Park and Ngel Nyaki Forest Reserve (Chapman and Chapman, 2001), but trade in P. africana bark trade in Nigeria is not well known, but Chapman (2004) reported extensive debarking in the Ngel Nyaki Forest Reserve in 2003. CITES placed P. africana as an Appendix II listed species in Cameroon and Democratic Republic of Congo in 1995, meaning that the species may become threatened if trade is not regulated (CITES 2006). Nigeria is a signatory to many international environmental-related treaties and conventions, while the nation has promulgated many such laws to ensure sustainable use and conservation of natural resources within her political boundary. But the problem has always been the poor implementation, fuelled by corruption within government circles. Many of the National Parks are so huge, yet poorly staffed such that proper monitoring of the parks is not done (WCS, 2010). One of such is the Gashaka Gumti National Park where monitoring staff find it difficult to cover the entire boundaries of the park, but enlists the help of the enclave and neighbouring villages to report poaching. In addition, Meduna et al. (2009) and Ijeoma and Ogbara (2013) also reported inadequate staffing, poor remuneration for staff and lack and poor maintenance of equipment as some of the problems in Kainji Lake National Park. Meduna et al. (2009) and Oseni (2007) also reported widespread encroachment in Old Oyo National Park and Yankari Game reserve. These grave situations are common in many other protected areas in Nigeria. As a result, a wide range of illegal activities are being perpetrated by poachers, farmers and tree fellers. The Wildlife Conservation Society reported over 600 illegal farms within the Afi River Wildlife Sanctuary alone (WCS, 2010). USAID (2008) reported that almost 1,000 forest reserves exist on the world database of protected areas of the IUCN; most of them have been seriously degraded or de-reserved. The felled indigenous trees are replaced by Tectonia grandis (Teak), Gmelina arborea (Gmelina) and other exotic tree species. Worse still, many protected areas such as Cross River National Park, Gashaka Gumti National Park (USAID, 2008) and Omo Biosphere reserve still harbour enclave villages till date, most of whom use clear the land for agriculture. An effort by a State Government in Southwest Nigeria to forcefully eject the enclave villages from a protected area resulted in violence and long legal battle which is probably yet to be resolved. This study also provokes the need to generate baseline information on the species diversity and the population ranges of the plants (and animals) in Nigeria. From this data collection, the national red list of threatened species in Nigeria can be compiled and proper conservation priority can be given to them. The present lack of data on the species was noted in FAO (2000) and USAID (2008), while there are so many discrepancies on the different lists of threatened plants in Nigeria. Furthermore, the degree of threats to those species was not provided in existing wide varieties of lists of plants adjudged to be endangered. Proper attention should be given to wild relatives of crop plants facing genetic erosion, trees with high medicinal values for their barks, plants with low distribution range, all endemic plants in Nigeria, indigenous grasses facing annual wildfires (especially in the afro-montane regions), economic timber species, epiphytic orchids, bryophytes and lichens among others. There is the need to intensify efforts on the domestication of all indigenous trees species in Nigeria, as well as consider an ex-situ conservation of such species. The protected area staffs needs to be trained and equipped with modern equipment for personal safety and effective monitoring. Adequate funding from Government budget should be allocated to them, while international and corporate bodies’ funding should be maximally explored. Eliminating the enclave villages in the protected areas may be very difficult; therefore, community-based natural resources management may be a viable option for managing the crisis between the enclave villagers and the Government. Since only 21 of 165 endemic plants in Nigeria have been evaluated by IUCN, there is the need to evaluate the rest, as well as other plants that were identified by several authors as endangered in Nigeria. One of such is Okoubakha aubrevillei, which is one of 2 species in the genera, both endemic to tropical Africa. Ladipo et al. (2008) reported for PROTA database that this tree noted that it is very rare in all its range. Few stands were sighted in some forest reserves in Edo State, but they are coppices from the felled old tree (Isikhuemen and Iduozee 2008). Botanical records for this tree species are scanty (Cunningham, 1993) and the only published study on this species by Veenendaal et al. (1996) was on its hemi-parasitic properties. Cunningham (1993) recommended damage assessments be carried out for this species, as well as Garcinia afzelii, G. kola, Griffonia simplicifolia and Pausinystalia johimbe. Seed germination for Okoubakha is extremely poor (Hawthorne, 1995), as trials carried out in National Centre for Genetic Resources and Biotechnology, Ibadan in the 2000s yielded only 3 seedlings (NACGRAB, 2004). The bark of the tree is exploited heavily for medicinal purposes. The tree is considered a sacred tree in many parts of Southern Nigeria, with many incantations and folklores about it, while some tribes worship it as a god. The barks were seen in an herbal market in Ibadan, Nigeria, while the herb seller claimed it is very scarce to get the bark, hence it is relatively expensive than other medicinal tree barks on sale (Borokini and Clement, 2012). 130 Online version available at: www.crdeep.com CRDEEP Journals SJIF IMPACT FACTOR (2013): 4.183 International Journal of Environmental Sciences Borokini, T.I Vol. 3 No. 3 ISSN: 2277-1948 This study was conducted to close the knowledge gaps and provide baseline information on the threatened plants in Nigeria for proper conservation management. It is believed that this information would encourage Nigerian scientists to focus more research on these species, while relevant Government and non-Government organizations will ensure the sustainability of these threatened species. Furthermore, it is believed that this study will chart the course towards the development of Nigeria’s red list of threatened species. References Adebisi, AA (2004). 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A Systematic Compilation of IUCN Red-listed Threatened Plant Species in Nigeria

A Systematic Compilation of IUCN Red-listed Threatened Plant Species in Nigeria

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