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International Journal of Environmental Sciences
Borokini, T.I
International Journal of Environmental Sciences Vol. 3 No.3. 2014. Pp.104-133
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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
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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.
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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.
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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Shrub
Shrub
Tree
Epiphyte
Epiphyte
Tree
Tree
Herb
Tree
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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
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shrub
Tree
Tree
Shrub
Tree
Tree
Tree
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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
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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
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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
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Herb
Herb
Herb
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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
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Tree
Tree
Epiphyte
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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.
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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
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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
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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
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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
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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
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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
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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
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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
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(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
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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
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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
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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
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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
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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
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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).
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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.
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