Blumea 64, 2019: 225 – 230 www.ingentaconnect.com/content/nhn/blumea RESEARCH ARTICLE https://doi.org/10.3767/blumea.2019.64.03.04 A new species and a synopsis of the Hedyotis-Oldenlandia group (Rubiaceae: Spermacoceae) in Andaman & Nicobar Islands, India M.D. Nandikar1, K.C. Kishor1 Key words Andaman & Nicobar Islands Hedyotis-Oldenlandia India new species typification Abstract An identification key to all the reported species of Hedyotis-Oldenlandia group (Hedyotis, Oldenlandia, Exallage, Leptopetalum, Scleromitrion and Debia) in Andaman & Nicobar Islands is presented with one new species, Oldenlandia smita-crishnae, described from Saddle Peak forests of North Andaman, India. It shares some characters with Oldenlandia herbacea, O. corymbosa and O. pseudocorymbosa. However, it is remarkable for its abaxially puberulous leaves, divaricate stipules, ellipsoid to obovoid hypanthium, pink-striped corolla lobes and 20 – 30-seeded, inserted capsule. Furthermore, a new combination in Exallage is proposed and lectotypes for Spermacoce cristata, S. costata, Hedyotis vestita and Oldenlandia stocksii are designated. Published on 27 September 2019 INTRODUCTION Hedyotis L. and Oldenlandia L. are two of the largest genera in the family Rubiaceae, with a total of about 515 species, and are distributed throughout the tropics, especially the old world (Terrell & Robinson 2003, Dutta & Deb 2004, Mabberley 2008). The genus Hedyotis has been in a taxonomic flux for a long time due to its variable circumscription. It has often been confused with Oldenlandia and has been treated with other related genera as the Hedyotis-Oldenlandia complex (Guo et al. 2013, Wikström et al. 2013, Neupane et al. 2015) in the tribe Spermacoceae (Brermer & Manen 2000). Traditional approaches to merge these genera, Hedyotis, Houstonia, Kadua, Kohautia and Oldenlandia, in a broader Hedyotis (Fosberg 1943, Merrill & Metcalf 1946, Lewis 1961, Rogers 1987, Wagner et al. 1989, Fosberg & Sachet 1991, Dutta & Deb 2004) are not supported by phylogenetic analysis of the tribe Spermacoceae in which 13 monophyletic genera are upheld (Debia, Dentella, Dimetia, Edrastima, Exallage, Hedyotis, Involucrella, Kadua, Kohautia, Leptopetalum, Neanotis, Oldenlandia and Scleromitrion) (Neupane et al. 2015). Hooker (1880) treated Hedyotis and Oldenlandia as distinct genera and recorded 57 and 23 species, respectively, for British India. Dutta & Deb (2004) in their revision of the genus Hedyotis for the Indian subcontinent included Oldenlandia in Hedyotis s.lat. and described and illustrated 74 species in 7 different sections. For Andaman & Nicobar Islands, Murugan et al. (2016) enumerated Hedyotis with 4 species and Oldenlandia with 8 species. This enumeration is expanded here by adding Exallage paradoxa, Oldenlandia graminicola, O. pseudocorymbosa and O. pumila. The Hedyotis-Oldenlandia complex in Andaman & Nicobar Islands In the present article we follow the recent generic circumscriptions in the Hedyotis-Oldenlandia complex (Neupane et al. 1 Naoroji Godrej Centre for Plant Research (NGCPR), Lawkim Campus, Shindewadi, Post Shirwal, District Satara, Maharashtra, India - 412801; corresponding author e-mail: mnandikar@gmail.com. 2015), and recognise 17 species from Andaman & Nicobar Islands in six genera: Debia, Exallage, Hedyotis, Leptopetalum, Oldenlandia and Scleromitrion. The genus Debia Neupane & N.Wikstr. is represented by the endemic D. andamanica (Kurz) Neupane & N.Wikstr. (Hedyotis andamanica Kurz) and can be recognised in the field by its ovate leaves and ridged hypanthium. The genus Exallage Bremek. can be separated from the remaining species in the Hedyotis-Oldenlandia complex by its crustaceous, hard, indehiscent, globose fruits, it includes four species: an endemic E. paradoxa (Kurz) Bremek. (H. paradoxa Kurz); E. insularis (Spreng.) Neupane & N.Wikstr. (Spermacoce insularis Spreng.) known from India and Southeast Asia; E. auricularia (L.) Bremek. (Hedyotis auricularia L.) distributed throughout tropical Asia (Fukuoka 1970, Terrell & Robinson 2003, Dutta & Deb 2004) and Exallage cristata (Willd. ex Roem. & Schult.) Nandikar & K.C.Kishor, a new combination for Spermacoce cristata Willd. ex Roem. & Schult. It is distributed in Andaman & Nicobar Islands, North India, Caroline Islands, China and Southeast Asia (Fukuoka 1970, Fosberg & Sachet 1991, Dutta & Deb 2004). Exallage costata (Roxb.) Bremek. (1952) and Hedyotis vestita R.Br. ex G.Don (1834: 526, erroneously cited as 527 by Terrell & Robinson 2003, Dutta & Deb 2004) is found to be conspecific with E. cristata. The genus Hedyotis is represented in Andaman & Nicobar Islands by a sole species H. congesta R.Br. ex G.Don which also occurs in Malaysia and Indonesia (Dutta & Deb 2004). The genus is characterised by having perennial herbs or shrubs and septicidally dehiscing capsules. The occurrence of this species listed by Fukuoka (1970) under H. philippensis (Wild. ex. Spreng.) Merr. ex C.B.Rob. (1911) (Spermacoce philippensis Wild. ex Spreng.) in Thailand appears to be a mistake, as he has synonymised H. congesta R.Br. ex G.Don (1834) instead of H. congesta Merr. (1906), which is an illegitimate, later homonym. Hedyotis congesta has been included as synonym of H. prostrata Blume (www.plantsoftheworldonline.org) which needs to be verified, as the latter species is a weak decumbent herb, while the former is an erect shrub. Leptopetalum is represented with two taxa in Andaman & Nicobar Islands and can be characterised by its ridged or winged © 2019 Naturalis Biodiversity Center You are free to share - to copy, distribute and transmit the work, under the following conditions: Attribution: You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Non-commercial: You may not use this work for commercial purposes. No derivative works: You may not alter, transform, or build upon this work. For any reuse or distribution, you must make clear to others the license terms of this work, which can be found at http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode. Any of the above conditions can be waived if you get permission from the copyright holder. Nothing in this license impairs or restricts the author’s moral rights. Blumea – Volume 64 / 3, 2019 226 hyapanthium: Leptopetalum biflorum (L.) Neupane & N.Wikstr. (Oldenlandia biflora L.) and L. pteritum (Blume) Neupane & N.Wikstr. (Hedyotis pterita Blume), both distributed throughout tropical Asia (Fukuoka 1970, Dutta & Deb 2004). Likewise, the genus Scleromitrion (Wight & Arn.) Meisn. is also represented by two taxa, and has strictly axillary flowers and exerted stamens with distinct filaments: Scleromitrion tenelliflorum (Blume) Korth. (H. tenelliflora Blume) and S. verticillatum (L.) R.J.Wang (Oldenlandia verticillata L.) are distributed throughout tropical Asia (Fukuoka 1970, Dutta & Deb 2004), the former is also known from Australia (Halford 1992). The genus Oldenlandia is represented in Andaman & Nicobar Islands with six species and can be recognised by a combination of characters: linear-lanceolate leaves, solitary to manyflowered cymes, usually inserted stamens and loculicidally dehiscent capsules. Oldenlandia graminicola (Kurz) Deb & M.Gangop. (Hedyotis graminicola Kurz) is an endemic to Andaman & Nicobar Islands; O. pumila (L.f.) DC. (H. pumila L.f.) is distributed in India, Bangladesh, Sri Lanka and Southeast Asia; O. corymbosa L. is common throughout tropical Africa and Asia and introduced in America and Australia; O. diffusa (Willd.) Roxb. (H. diffusa Willd.) and O. pseudocorymbosa (Bakh.f.) Raizada (H. pseudocorymbosa Bakh.f.) are known throughout India and Southeast Asia and O. wallichii Craib (H. wallichii Kurz) is distributed in India (Nicobar Islands) to Southeast Asia (Fukuoka 1970, Dutta & Deb 2004). The occurrence of O. wallichii (as Hedyotis kurzii) in mainland India (Kerala and Karnataka, Rashmi & Krishnakumar 2015) is mistaken, as one of the key characters ‘capsule crowned by calyx’ (Kurz 1876) is completely absent in their specimen, as we have confirmed with the help of capsule photographs in their article. In addition, no voucher specimen (Rashmi & Krishnakumar 642) appear to be housed at MH. The species diagnosis by Rashmi & Krishnakumar (2015) is more similar to the description for H. kurzii by Dutta & Deb (2004), except for the globose and lobed fruit which is unusual in the genus Oldenlandia. The genus Oldenlandia keys out based on its annual habit (Neupane et al. 2015); however, some Oldenlandia species (O. graminifolia, O. herbacea, O. pumila) have a perennial woody rootstock which accordingly appears to be a too variable character to circumscribe the genus. Saddle Peak National Park, the highest mountain peak in the Andaman Islands is known for its coastline, stunted evergreen forests with mixed patches of rocky outcrops and open scrub habitats and harbours many endemic taxa (Reddy & Prasad 2008). In our recent botanical expedition to the Saddle Peak National Park, we have collected an Oldenlandia plant with pink-striped corolla lobes from an open scrub forest in rocky situations of the Saddle Peak forest of North Andaman. A careful study of the collected species and thorough scrutiny of the literature (Hooker 1880, Fukuoka 1970, Terrell & Robinson 2003, Dutta & Deb 2004, Alejandro 2007, Murugan et al. 2016) revealed several morphological differences from the known taxa of genus Oldenlandia. It is described here as Oldenlandia smita-crishnae, which has been keyed out here along with all the reported species of Hedyotis-Oldenlandia complex in Andaman & Nicobar Islands, for ease of identification. Furthermore, Spermacoce cristata, S. costata, Hedyotis vestita and Oldenlandia stocksii Hook.f. are lectotypified. TAXONOMY Oldenlandia smita-crishnae Nandikar & K.C.Kishor, sp. nov. — Fig. 1, 2 Type: M.D. Nandikar & K.C. Kishor 2118 (holo CAL; iso K, NGCPR, PBL), India, Andaman & Nicobar Islands, North Andaman, Saddle Peak National Park, N13.15'541" E093.01'884", elevation 513 m a.s.l., 7 Oct. 2017. Etymology. Named after Mrs. & Mr. Crishna (Smita Godrej Crishna and Vijay Mohan Crishna), Directors of the Naoroji Godrej Centre for Plant Research in Shirwal, Satara, India, to honour their promotion of plant taxonomy and conservation. Erect, 5 – 20 cm high, annual or perennial herb. Roots thin, fibrous, often with woody rootstock. Stem usually branched, terete, light green tinged with pink, glabrous. Leaves stipulate, stipule divaricate with two small basal projections, 1.5–2.5 by 0.1–0.3 mm, ligulate, sparsely toothed on the margin; leaf lamina sessile, linear-elliptic or lanceolate, 1–2 by 0.1–0.3 cm, apex acute, base attenuate, margin puberulent, adaxially glabrous, abaxially puberulous. Inflorescence axillary, solitary or a 2-flowered cyme. Flower pedicellate, pedicel 1– 2 cm long, glabrous, filiform; flower homostylous, 6 –7.5 mm long; hypanthium obovoid, 1– 3 by 0.5–1.5 mm; calyx lobes 4, lanceolate, base obtuse, green with pink tinge, margin with small setae, pink, midrib prominent; corolla infundibuliform, 4 – 5 mm long; tube slender, 1– 2 mm long, white, glabrous without and sparsely to densely puberulous within (at throat); lobes 4, elliptic-lanceolate, 2–2.5 by 0.3–1 mm, apex acuminate, white with pink aciculated, gla- Table 1 Morphological comparison between Hedyotis smita-crishnae and similar species. Characters H. smita-crishnae H. herbacea Habit H. corymbosa H. pseudocorymbosa Annual or perennial herb Annual or perennial herb Annual herb Annual herb Stem shape Terete Acutely angular or 4-ribbed Acutely angular or cylindrical Terete Leaf margin abaxial surface stipule Puberulent to scabrid Puberulous Divaricate with two small basal projection Glabrous Glabrous Truncate with few setae on the margin Glabrous or pubescent Glabrous Fimbriate with 2 – 4 lobes Scabrid Scabrid on midrib Pectinate with few teeth Inflorescence Usually solitary, rarely 2-flowered axillary cyme Solitary or in paired cyme 2 – 5-flowered corymbose, umbels or racemose cymes 2 – 5-flowered axillary cyme Flower calyx lobes corolla tube 10 – 20 mm Obovoid 1– 3 mm Lanceolate White with double-lined pink stripe Puberulous at the throat inside 6 – 22(– 30) mm Ovoid 0.8 –1 mm Triangular White or white with purple spots Glabrous inside 2.5 –14 mm Globose 0.7–1 mm Narrowly triangular White or white with red tinge above Glabrous inside lobes length hypanthium Elliptic-lanceolate Ovate 1–10 mm Ellipsoid or ovoid 0.7–1 mm Narrowly triangular White Ring of pubescent hairs in mouth of the tube Ovate Stamen anther filament Linear to oblong Inconspicuous Linear 0.1– 0.2 mm Subglobose 0.2 – 0.8 mm Globose 0.1– 0.2 mm Capsule Globose-obovoid, apex not protrude beyond calyx segment Ovoid or subglobose, apex protrude beyond calyx segment Globose, apex slightly protrude beyond calyx Globose, apex slightly protrude beyond calyx segments Ovate 227 M.D. Nandikar & K.C. Kishor: Hedyotis-Oldenlandia group in Andaman & Nicobar Islands b f c d g e a Fig. 1 Hedyotis smita-crishnae Nandikar & K.C.Kishor. a. Habit; b. stipule; c. flower; d. opened corolla with adnate stamens; e. capsule; f. pistil with hypanthium; g. seeds (ventral and lateral view) (all M.D. Nandikar & K.C. Kishor 2118, CAL). — Scale bars: a – b, e = 1 mm; c = 1.2 mm; d = 0.6 mm; f = 0.7 mm; g = 0.8 mm. — Drawn by Mayur D. Nandikar. brous without and double lined pink-striped, sparsely puberulent within (densely at margin). Stamens 4, included, filament inconspicuous; anther linear to oblong, 0.8–1 mm long, erect, equal, bilobed, adnate to corolla tube, dorsifixed; pollen periporous, 100 –130 by 90 –100 µm, prolate-spheroidal to subprolate in shape. Ovary globose or ovoid, 1.5 – 2 mm across, glabrous; style slender, 3 – 4 mm long, glabrous; stigma bilobed, exceeding corolla tube. Capsule globose or ovoid, 2–2.5 by 1–1.5 mm, bilocular, crowned by persistent protruding calyx lobes. Seeds 20 – 30 per capsule, outline deltoid, 0.3 – 0.4 by 0.1– 0.2 mm, ventrally ellipsoid, dorsally obovoid, testa reticulate-foveate, shiny, dark greyish brown, hilum punctiform. Phenology — Flowering and fruiting throughout the year, but peak during October. Distribution & Ecology — An endemic to the Saddle Peak National Park, North Andaman, Andaman & Nicobar Islands, India. It grows abundantly in an open scrub forest of the Saddle Peak forest of North Andaman, mainly preferring open rocky situations of the mountain peak at an elevation of 500 – 540 m a.s.l. The associated plant species include Crotalaria uncinella Lam. subsp. elliptica (Roxb.) Polhill, Dioscorea belophylla (Prain) Voigt ex Haines, Grewia indandamanica J.L.Ellis & L.N.Ray, Memecylon umbellatum Burm.f., Murdannia saddlepeakensis M.V.Ramana & Nandikar and Sonerila andamanensis Stapf & King. 228 Blumea – Volume 64 / 3, 2019 a c b d Fig. 2 Hedyotis smita-crishnae Nandikar & K.C.Kishor. a. Habitat from Saddle Peak National Park; b. habit; c. upper view of flower; d. lateral view of flower. — Photos by Mayur D. Nandikar. M.D. Nandikar & K.C. Kishor: Hedyotis-Oldenlandia group in Andaman & Nicobar Islands Conservation status — An estimation of area of occurrence (AOO) of the species is unworkable, as some of the forest patches of the Saddle Peak National Park are inaccessible. Therefore, it is here assessed as Data Deficient (DD), using the criteria of IUCN (2017). The first collection of Oldenlandia smita-crishnae was in 2001 (Sumathi 17367, PBL) labelled as ‘abundantly distributed’, we also found the species growing abundantly and one of the commonest herbaceous elements in open, rocky situations of the hilltop, and apparently not under threat. Additional material examined (paratypes). IndIa, Andaman & Nicobar Islands, North Andaman, Saddle Peak, R. Sumathi 17367 (PBL0000010026, PBL0000010027), 18 Apr. 2001. Notes — Oldenlandia smita-crishnae is similar to O. corymbosa, O. pseudocorymbosa and O. herbacea in a combination of characters like erect or prostrate habit, sessile to subsessile leaves and globose to ovoid ovary. However, the new species can be easily distinguished by the abaxially puberulous leaf, divaricate stipules, obovoid hypanthium, pink-striped corolla lobes, puberulous tube, inserted and 20 – 30 seeded capsules. A detailed comparison of O. smita-crishnae with O. herbacea, O. corymbosa and O. pseudocorymbosa is given in Table 1. Oldenlandia smita-crishnae is also similar to O. affinis and O. graminicola in flower size and shape but the latter two differ by having terminal dichasial cymes and lax panicles. Moreover, O. graminicola has an angular stem, truncate stipules and scabrid pedicels, while O. smita-crishnae has terete stems, divaricate stipules and glabrous pedicels. Oldenlandia horneriana Miq. (non Kuntze), an endemic species of Sumatra also shares similarities with O. smita-crishnae in being an annual with erect habit, linear leaves and infundibuliform corolla, but mainly differs in having angular stem, and distinctly exerted anthers. NEW COMBINATION & TYPIFICATION OF THE NAME Exallage cristata (Willd. ex Roem. & Schult.) Nandikar & K.C.Kishor, comb. nov. Spermacoce cristata Willd. ex Roem. & Schult. Syst. Veg., ed. 15(3) (1818) 530. — Type: Roxburgh s.n. (lectotype, perhaps holotype: B (barcode B -W 02619 -01 0, http://herbarium.bgbm.org/object/BW02619010), here designated), India, in Willdenow Herb., s.dat. Spermacoce costata Roxb. (1814) 10, nom. nud.; (1820) 376. — Hedyotis costata (Roxb.) Kurz (1876) 135, nom. illeg.; non R.Br. ex G.Don (1834). — Exallage costata (Roxb.) Bremek. (1952) 142. — Type: Roxburgh s.n. (lectotype BR (barcode BR0000005316632), here designated), s.loc., s.dat. Hedyotis vestita R.Br. ex G.Don (1834) 526. — Type: R.Brown s.n. (lectotype BM (barcode BM000833378, http://data.nhm.ac.uk/object/d9335565-68654070-aa48-9286cef8ac85), here designated), 1822; isolectotypes BM (BM001217239), CAL (CAL0000069601; CAL0000069602), K (K000770018; K001110053), Malaysia, P. Penang. Notes — A specimen has been traced at B, Willdenow Herbarium (B -W 02619 -01 0) annotated by Willdenow as S. cristata, originally collected by Roxburgh as S. costata; it is chosen here as lectotype. Another specimen collected by Roxburgh is at BR (BR0000005316632) with an annotation by Roxburgh as ‘S. costata duplicate’. It is not certain that this is a duplicate of the lectotype specimen, and it bears no annotation by Willdenow. It is here selected as lectotype of S. costata, which is then a heterotypic synonym of S. cristata. The name Hedyotis vestita is based on Robert Brown’s collections from Penang and Sylhet. It appeared first in Wallich’s Catalogue and was later validated by Don (1834). We could find multiple specimens from both Penang and Sylhet labelled no. 847 (1/A and 2/B) at BM, CAL and K. One of the specimens from Penang (Wall. Cat. no. 847.1/A barcode BM000833378) 229 is here selected as lectotype, duplicates at CAL and K are isolectotypes. Oldenlandia stocksii Hook.f. Oldenlandia stocksii Hook.f. (1880) 67. — Type: Stocks s.n. (lectotype K (barcode K000031278, http://specimens.kew.org/herbarium/ K000031278), here designated), s.dat.; isolectotypes A (A01154646), BR (BR0000005587308, BR0000005587629), CAL (CAL0000010806, CAL0000010809), F (F0069816F), GH (GH00097088), K (K000031279), L (L.2917167, L.2917168), M (M0198369, M0198370), MPU (MPU021357), P (P03984807, P03984808, P05459154), S (S14-14477, S14-14484), India, Karnataka, Chikkamagaluru District, Bababooden hills (Baba Budan hills), s.dat. Note — Hooker in 1880 described Oldenlandia stocksii in Flora of British India on basis of the collection made by Stocks & Law from ‘Malabar, in the Bababooden hills (Baba Budan hills)’ with no further information provided. Various collections made by Stocks from Malabar (1847–1851) are incorporated in Herbarium Indiae Orientalis by Hooker & Thomson (Stafleu & Cowan 1986). During the present investigation we also traced collections at P (3 sheets), BR, CAL, K, L, M and S (2 sheets in each) and single sheets at A, F, GH, H and MPU. All sheets are in agreement with the protologue and can be regarded as syntypes. As the primary repository of Hooker is at K, we selected the specimen barcode number K000031278 as lectotype, the remaining specimens are isolectotypes. KEY TO THE HEDYOTIS-OLDENLANDIA GROUP IN ANDAMAN & NICOBAR ISLANDS 1. Perennial herbs or shrubs; inflorescence an axillary head or umbel; flowers usually subsessile, crowded . . . . . . . . . . 2 1. Annual herbs; inflorescence terminal, terminal and axillary, an axillary cyme, corymbose or capitate; flowers distinctly pedicellate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Capsule hemispherical, dehiscing septicidally . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hedyotis congesta 2. Capsule globose, crustaceous or hard, indehiscent . . . . 3 3. Villous or puberulous herbs; leaves ovate-lanceolate or elliptic-lanceolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Sparsely pubescent to glabrous herbs or shrubs; leaves linear-lanceolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Stipule with 2–7, puberulous projections, leaf base cuneate, apex acute . . . . . . . . . . . . . . . . . . . . . Exallage auricularia 4. Stipule with 1– 3, villous projections, leaf base attenuate, apex acuminate . . . . . . . . . . . . . . . . . . . . Exallage cristata 5. Stipules with 3 linear, unequal projections; apex of corolla lobes glabrous; stigma clavate . . . . . . . Exallage insularis 5. Stipules with 6 –10 filiform, unequal projections; apex of corolla lobes sparsely tomentellous; stigma bilobed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exallage paradoxa 6. Leaves ovate, elliptic or obovate; hypanthium distinctly ridged; calyx teeth usually recurved . . . . . Debia andamanica 6. Leaves usually linear-lanceolate, linear, elliptic-lanceolate or obovate; hypanthium smooth; calyx teeth porrect . . . . 7 7. Stem terete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7. Stem angular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8. Flowers 2–5 mm long, hypanthium globose, corolla tubular, lobes pink-white or white with red tinge, mouth of the corolla tube glabrous within . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8. Flowers 6 –7.5 mm long, hypanthium obovoid, corolla infundibuliform, lobes white with double-lined pink stripe, mouth of the corolla tube puberulous within . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oldenlandia smita-crishnae 230 9. Stem scabrid; flowers 2 – 3 mm long, calyx lobe narrowly triangular . . . . . . . . . . . . Oldenlandia pseudocorymbosa 9. Stem glabrous; flowers 4 – 5 mm long, calyx lobe ovatelanceolate . . . . . . . . . . . . . . . . . . . . . Oldenlandia diffusa 10. Inflorescence strictly axillary; flowers homostylous; stamens exserted, filaments distinct . . . . . . . . . . . . . . . . 11 10. Inflorescence axillary and terminal; flowers heterostylous; stamens inserted, filaments inconspicuous . . . . . . . . . 12 11. Stipule deltate; inflorescence 2 – 4-flowered; filaments 2 – 2.5 mm long; stigma bifid; capsule glabrous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scleromitrion tenelliflorum 11. Stipule cupular; inflorescence with clusters of 4 –10(–16)flowers; filaments 4–4.6 mm long; stigma bilobed; capsule hispid . . . . . . . . . . . . . . . . . . . . Scleromitrion verticillatum 12. Hypanthium ridged or winged . . . . . . . . . . . . . . . . . . . 13 12. Hypanthium smooth . . . . . . . . . . . . . . . . . . . . . . . . . . 14 13. Decumbent, sparsely branched herbs; cymes 2-flowered, stamens inserted in the sinus of corolla lobes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leptopetalum biflorum 13. Erecto-patent, diffusely branched herbs; cymes 3 – 8-flowered; stamens adnate to corolla tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leptopetalum pteritum 14. Stem glabrous or pilose; flowers in umbels, corymbs or many-flowered branched cymes . . . . . . . . . . . . . . . . . 15 14. Stem scabrous; flowers solitary or in 2-flowered cymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 15. Stamens inserted at the sinus of corolla lobes; stigma bifid . . . . . . . . . . . . . . . . . . . . . . . . . Oldenlandia wallichii 15. Stamens adnate to the corolla tube; stigma bilobed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oldenlandia corymbosa 16. Leaves elliptic or elliptic-lanceolate; flowers 2.5 – 3 mm long; stigma with tufted hairs . . . . . . . Oldenlandia pumila 16. Leaves linear-lanceolate; flowers 7– 8 mm long; stigma glabrous . . . . . . . . . . . . . . . . . . . Oldenlandia graminicola Acknowledgements The authors are grateful to Mr. & Mrs. Crishna, Directors NGCPR, for their constant support and providing research facilities, Dr. Nilesh V Malpure, S.S.G.M. College, Kopergaon, Ahmednagar for his assistance during field collection, Smt. Arti Chaudhary, Conservator of Forest (WL), Andaman & Nicobar Islands for endorsing forest permission and Drs. Lal Ji Singh and Vivek, Botanical Survey of India (PBL), Andaman & Nicobar Regional Centre, for their substantial help in consultation of herbarium and library. We are also thankful to the authorities of A, B, BR, CAL, F, H, K, L, M, MH, MPU, P and S herbaria for making images/data available online and their responses over e-mail. Blumea – Volume 64 / 3, 2019 REFERENCES Alejandro GJD. 2007. The current status of the Philippine Rubiaceae. Philippine Journal of Systematic Biology 1(1): 47– 60. Bremekamp CEB. 1952. The African species of Oldenlandia L. sensu Hiern et K. Schumann. Verhandelingen der Koninklijke Nederlandsche Akademie van Wetenschappen. Afdeeling Natuurkunde 48(2): 142. Bremer B, Manen JF. 2000. Phylogeny and classification of the subfamily Rubioideae (Rubiaceae). Plant Systematics and Evolution 225: 43 –72. Don G. 1834. 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