Telopea Volume 18: 171-176 The Royal Publication date: 31 July 2015 Botanic Gardens Journal of Plant Systematics dx.doi.org/10.7751/telopea8862 & Domain Trust plantnet.rbgsyd.nsw.gov.au/Telopea • escholarship.usyd.edu.au/journals/index.php/TEL • ISSN 0312-9764 (Print) • ISSN 2200-4025 (Online) Eria merguensis Lindl. (Orchidaceae) - a new addition to the Indian flora S.K. Singh1, Ramesh Kumar1, Avishek Bhattacharjee23, Sachin Sharma 1 botanical Survey of India, Eastern Regional Centre, Lower New Colony, Laitumkhrah, Shillong - 793 003, Meghalaya, India 2Central National Herbarium, Botanical Survey of India, A.J.C.B. Indian Botanic Garden, Howrah -711 103, West Bengal, India. 3 Author for correspondence: [email protected] Abstract Eria merguensis Lindl., an uncommon orchid, is reported here for the first time from India. The conservation status of the species is discussed in Indian context. Introduction The genus Eria Lindl. sensu lato (Orchidaceae: Epidendroideae: Eriinae) is highly polymorphic and represented by c. 500 species (Pridgeon 1992), distributed from Sri Lanka to Tahiti (Ormerod 2014). In India, Eria s.l. is represented by 60 taxa (Agrawala and Chowdhery 2013). The circumscription of the genus Eria is still controversial. Lindley (1858) recognized 11 sections, Bentham (1881) recognized 10 sections, Kranzlin (1911) recognized 8 sections under Eria. Seidenfaden (1982) provided a list of 41 sectional names in Eria in his treatment. Cribb et al. (2005) reinstated several earlier recognized genera that had been reduced to sectional ranks, but their concepts have not been accepted in some recent works (Agrawala and Chowdhery 2013; Agrawala and Ormerod 2014; Ormerod 2014) because the “circumscriptions of these genera are overlapping and not precisely defined” (Agrawala and Chowdhery 2013, p. 116); some segregate genera “seem difficult to define” and “the definition of the genus Callostylis Blume seems somewhat broad” (Ormerod 2014, p. 77). During field explorations between 2010 and 2013, the authors collected some plants of Eria from North Himen Village in the Kolasib district and Murlen National Park in the Champhai district, both within the State of Mizoram (Fig. 3). A voucher specimen of the first collection could not be prepared due to lack of flowers and scarcity of specimens. However, a single living clump was transplanted to the Orchidarium of the Botanical Survey of India, Eastern Regional Centre, Shillong for ex-situ conservation and further study Critical study of live plant material from North Himen and a herbarium specimen from Murlen National Park revealed their identity as Eria merguensis Lindl., a species hitherto unknown from India. © 2015 Royal Botanic Gardens and Domain Trust 172 Telopea 18: 171-176, 2015 Singh, Kumar, Bhattacharjee and Sharma Blume (1825) described the genus Mycaranthes with 3 species (Mycaranthes oblitterata Blume, M. latifolia Blume and M. lobata Blume). Reichenbach (1857) treated Mycaranthes as a section of Eria for the first time and placed all of Blume’s three species of Mycaranthes along with another species of Eria, viz. E. javensis Zoll. & Moritzi, in the section Mycaranthes (Blume) Rchb.f. Lindley (1858) described E. merguensis and placed it in section Mycaranthes along with E. stricta Lindl. and E. retusa (Blume) Rchb.f. Lindley (1858) had misapplied the sectional name Mycaranthes, and therefore the new section Secundae Leavitt was created to accommodate the misplaced species. Seidenfaden (1982) placed Eria merguensis in section Secundae with other species of Eria, viz. E. siamensis Schltr. and E. porteri Seidenf. & A.D. Kerr. In the present communication we prefer to follow Seidenfadens treatment but are aware that further studies may place Eria merguensis in a different section or genus for that matter. A detailed taxonomic account of the species is provided below. Taxonomic treatment Eria merguensis Lindl., Journal of the Proceedings of the Linnean Society Botany 3: 52 (1858); HG Reichenbach, The Gardeners Chronicle, new series 13: 616 (1880); Seidenfaden, Opera Botanica 62: 82 (1982). Pinalia merguensis (Lindl.) O. Kuntze, Revisio Generum Plantarum 2: 679 (1891). Mycaranthes merguensis (Lindl.) Rauschert., Feddes Repertorium 94: 456 (1983). Lectotype (designated by Seidenfaden 1982): Mergui, Griffith 1034 (K, image!, [as‘type by Seidenfaden, loc. cit.]); Residual syntype: Moulmein, Lobb s.n. (K-LINDL). Epiphytic, 8-20 cm tall herbs. Pseudobulbs crowded, clavate to cylindrical-clavate, 4-10 cm long, 0.5-1.2 cm wide. Leaves 2 or 3, arising from subapical nodes of pseudobulbs, oblong-ovate to oblong-lanceolate, 5- 11 cm long, 0.7-1.5 cm wide, blunt and unequal at apex, lamina narrowed to form c. 5 mm long petiole-like structure, midrib distinct. Inflorescence a subterminal raceme, 1 or 2 from a pseudobulb, erect, densely 16-68-flowered, flowers facing outwards in all directions, covered with white tomentose hairs; peduncle 2-6 cm long; rachis 2- 10 cm long. Floral bracts minute, c. 1 mm long, 0.5 mm wide. Flowers densely woolly externally, yellow; sepals similar, c. 1.5 mm long, 1.2 mm wide, ovate to ovate-orbicular, obtuse at apex, white tomentose outside, 3- veined, lateral sepals sometimes slightly oblique; petals ovate to oblong-ovate, c. 1.2 mm long, 0.8 mm wide, obtuse at apex. Lip obscurely 3-lobed, c. 1.4 long, subacute to obtuse at apex, with 2 fat parallel longitudinal calli; calli truncate and papillose at apex. Pollinia 8, yellow, clavate, each c. 0.3 mm long. Fig. 1,2. Flowering and fruiting: January-April Habitat: The plants are found growing on the branches of trees at the edges of tropical and subtropical forests, at elevations of 600-1600 m. Distribution: India (reported here), Myanmar, Thailand. Etymology: The generic name Eria is derived from the Greek cerw (wool) in reference to the outside of the sepals and petals, and the specific epithet is after the type-locality (Mergui) of the species. Specimens examined: INDIA: Mizoram, Champhai, Murlen National Park, 1550 m, 15 Apr 2013, Ramesh Kumaretal. 128466(ASSAM).MYANMAR:Moulmein,Jan 1897,Peches.n. (CAL);Feb 1897,Peches.n. (CAL); Mergui, Mar 1911 ,Meebold 14510 (CAL). Diagnostic features: Eria merguensis is morphologically similar to E. porteri (Seidenfaden 1982), a probable synonym of E. pudica Ridl., but can be distinguished by its dense, 16-68-flowered inflorescence (vs 10-12-flowered inflorescence in E. porteri), sepals c. 1.5 mm long (vs sepals c. 3 mm long in E. porteri) and papillose apices of labellum calli (vs smooth labellum calli in E. porteri). Further, the hairs on the pedicel plus ovary and sepals in E. merguensis are coarsely tomentose, where in E. porteri the hairs are finely tomentose. Eria merguensis - new record for India Telopea 18: 171-176, 2015 173 Fig. 1. Eria merguensis Lindl. a-b, habit; c, portion of rachis; d, flower. 174 Telopea 18: 171-176, 2015 Singh, Kumar, Bhattacharjee and Sharma Fig. 2. Eria merguensis Lindl. a, habit; b. Flower (front view); c, flower (basal view); d, sepals, petals, lip, column and pedicel plus ovary; e, anther (left) and pollinia; f, column. [Portions of an illustration (rearranged) at CAL prepared on a herbarium sheet (with a label) possibly by Robert Pantling] Eria merguensis - new record for India Telopea 18: 171-176, 2015 175 O O C O C a E O O M 2 & 2 Ofl M O Jfl D- 0 4 4 7 7 2 r f O M Ji 00 J 0 ^ 4 7 2 W O 0 J O 27 O M 1 7 2 W D W & S 0 i A 0 S G 2 H 0 H » Ofl <J 0 5 L 2 D W 9 O H D O 3 i o 2 W W Q 0 M D M0 5 2 C O Q O T O H O O O =i 2 ) W C M4 & 0 i O O 3 5 2 0 KI K C 1 M J5- M H C 5 2 101MM0 1C£Sa0C3 1025MM lOMOMO W31QOD0 lC^flOCS 102 70G0C H^aOCaC- 1£i20-3C3 104«M0I> Fig. 3. Map (with 10 x 10 km grids) showing distribution of Eria merguensis Lindl. in India, 176 Telopea 18: 171-176, 2015 Singh, Kumar, Bhattacharjee and Sharma Conservation status in India: Endangered [EN Blab(ii) D] Eria merguensis is presently reported only from three countries, viz. India (here reported), Myanmar and Thailand. In India, we could locate c. 150 mature individuals (Criterion D) of E. merguensis growing in 2 localities in the State of Mizoram (Fig. 3), i.e. in forests of North Himen village, Kolasib and Murlen National Park, Champhai. In India, the Extent of Occurrence (EOO, Criterion Bl) of E. merguensis is c. 3000 sq km and Area of Occupancy (AOO, Criterion B2) is c. 8 sq km. However, we predict that the AOO may be slightly higher (but of course <500 sq km) as the species may occurs in a few more nearby locations due to similar type of habitat and species-composition. We have not observed any natural or man-made threat to this epiphytic species in Murlen National Park (Protected Area), but it is under moderate threat near the North Himen village due to dependency of the tribal people on the forest. Based on its EOO (Criterion Bl), the number of mature individuals (Criterion D) and the present threat (near North Himen village) we assessed E. merguensis as Endangered [EN Blab(ii) D] in India as per IUCN’s guidelines (IUCN, 2012). The status of E. merguensis at global level could not be assessed at present due to lack of sufficient data on Thai and Burmese specimens and their present populations. Acknowledgments The authors are thankful to the Director, Botanical Survey of India, Kolkata for facilities and to Head of Office, Botanical Survey of India, Eastern Regional Centre, Shillong for encouragement. Authors extend their sincere thanks to the officials of Forest Department, Mizoram for the logistic support during field explorations and the anonymous reviewers for refining the manuscript. One of the authors (AB) is thankful to Mr. Olivier Hasinger, SSC Network Support Officer, IUCN for providing ArcGIS software on behalf of IUCN/SSC for Red Listing of Indian orchids. The authors gratefully acknowledge the in-depth advice provided by two anonymous reviewers. References Agrawala DK, Chowdhery HJ (2013) Conspectus of the genus Eria Lindl. (Orchidaceae) in India. Journal of the Non-Timber Forest Products 20(2): 115-142 Agrawala DK, Ormerod P (2014) A New Species of Eria (Orchidaceae) from India under the Section Cylindrolobus. Taiwania 59(3): 206-209 Bentham G (1881) Notes on Orchideae. The Journal of the Linnean Society, Botany 18: 281-360 http://dx.doi.Org/10.llll/j.1095-8339.1881.tb01258.x Blume CL (1825) Bijdrajen Tot De Flora Van Nederlandsch Indie. P. 552. (Lands Drukker Ij: Batavia) Cribb PJ, Ng YP, Pridgeon AM, Wood J, Veitch NC, Grayer RJ (2005) Podochileae subtribe Eriinae. Pp. 532-587 In Pridgeon AM, Cribb PW, Chase MW, Rasmussen FN (eds.). Genera Orchidacearum Volume 4. (Oxford University Press: Oxford) IUCN (2012) Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. (IUCN: Gland, Switzerland and Cambridge, UK) Kranzlin F (1911) Orchidaceae-Monandrae-Dendrobiinae 2. Pp. 1-182 in Engler A (ed) Das Pflanzenreich Hft. 50. (Wilhelm Engelmann: Berlin) Lindley J (1858) Contribution to the Orchidology in India - No. 2. Journal of the Proceedings of the Linnean Society, Botany 3: 1-63 http://dx.doi.Org/10.llll/j.1095-8339.1858.tb02055.x Ormerod P (2014) A synopsis of Eria Lindl. (Orchidaceae) section Cylindrolobus (Blume) Lindl. (Orchidaceae: Eriinae) in Malesia. Harvard Papers in Botany 19(1): 77-95 http://dx.doi.org/10.3100/hpib.vl9issl.2014.n6 Pridgeon A (1992) What Orchid is that? Pp. 1-304. (Lansdowne Publishing Co.: Sydney) Reichenbach HG (1857) Orchideae Zollingerianae itineris primi recensentur. Bonplandia 5: 53-58 Seidenfaden G (1982) Orchid genera in Thailand X. Trichotosia Bl. and Eria Lindl. Opera Botanica 62: 1-128 Manuscript received 16 June 2015, accepted 23 July 2015