Pendulorchis (Orchidaceae) – A new generic record for Nagaland, India

· Articles
Authors

H.Y. Jakha1, C.R. Deb1 , S.K. Singh2*, D. Verma2, S. Dey1 & N.S. Jamir1

1Department of Botany, Nagaland University, Lumami- 798627, India
2Botanical Survey of India Eastern Regional Centre, Shillong-793003, India
*Corresponding author: S.K.Singh email: sksbsinc@rediffmail.com

Abstract

A spectacular orchid, Pendulorchis himalaica is reported here for the first time from Nagaland – a state of Northeastern India. This constitutes the first generic report to Nagaland. The same has been described and photographic illustration provided to facilitate its easier identification.

Keywords Pendulorchis, Orchidaceae, Nagaland, India

Introduction

The Pendulorchis Z.J. Liu, Ke Wei Liu & G.Q. Zhang (Orchidaceae) is a recently established genus based on molecular studies (Zhang et al., 2013). Two species viz., Pendulorchis gaoligongensis G.Q. Zhang, Ke Wei Liu & Z.J. Liu (type species of the genus) and P. himalaica (Deb, Sengupta & Malick) Z.J. Liu, Ke Wei Liu & X.J. Xiao are recognised under the genus and distributed in India, Myanmar, China and Bhutan. The genus is characterised by its epiphytic pendulous plant habit which bears many long and flattened roots, stem often 13 – 24 cm long enclosed by leaf sheaths and often branched, the leaves subterete 30 – 60 cm long 3 – 5 mm in diameter jointed and sheathed at the base; inflorescences often
6 – 15 paniculate or racemose arising from the axils of the lower leaves with 17 – 39 flowers; flowers 4 – 5 mm in diameter, not fully open; sepals petals and lip reddish, lip 3-lobed, side-lobe erect oblong, toward abaxial base strongly concave forming a callus-like structure, midlobe spreading forward, obovate, adaxially with three longitudinal mid-veins, spur cylindric, column stout and short; pollinia two, globose, cleft attached by a common stipe to a large suborbicular viscidium (Zhang et al., l.c.).

In India, only Pendulorchis himalaica is known to occur based on collection by Kingdon-Ward in 1946 from Manipur (Kumar & Kumar, 2005), and by J. Joseph 40360 (ASSAM) from Kameng district, Arunachal Pradesh (Deori & Das, 1976). However, it is mentionable that the aforesaid reports were known by other names either Saccolabium or Ascocentrum.

During a botanical exploration tour to the Tuensang district of Nagaland, India, in November 2014, two of us (SD & HYJ) encountered a spectacular plant bearing terete leaves and purplish flower having very long spur. On perusal of the literature (Zhang et al., 2013; Xinqi & Wood, 2009; Pearce & Cribb, 2002; Deori & Das, 1976), the identity of the same was confirmed as Pendulorchis himalaica, a less known species in Indian orchidology formerly placed under Ascocentrum or Saccolabium. The same is being reported here for first time from the Nagaland. It is also interesting to note that this constitutes the first generic report to the State. The studied herbarium specimen is deposited in Herbarium of Nagaland University. Photographic illustration is provided to facilitate its easier identification.

Taxonomic description

Pendulorchis himalaica(Deb, Sengupta & Malick) Z.J. Liu, Ke Wei Liu & X. J. Xiao, Plos One 8 (4): 8. 2013. Saccolabium himalaicum Deb, Sengupta & Malick, Bull. Bot. Soc. Bengal 22 (2): 213. 1968. Ascocentrum himalaicum (Deb, Sengupta, & Malick) Christenson, Notes Bot. Gard. Edinb. 44: 256. 1987. Holcoglossum himalaicum (Deb, Sengupta, & Malick) Averyanov, Bot. J. (Leningrad) 73 (1): 101 – 107. 1988. Holcoglossum junceum Z. H. Tsi, Acta Phytotax. Sin. 20 (4): 442. 1982.

Plants epiphytic; pendulous, with flattened roots arising from nodes. Stem 10 – 20 cm long, 5 – 8 mm in diameter, enclosed by leaf sheaths, upper part with 3 – 6 leaves. Leaves slender, terete, green, fleshy, 20 – 55 cm long, 0.3 – 0.6 cm in diameter, sheathed at base, apex acute. Inflorescence racemose, arising from the axils of the lower leaves 4 – 13 cm long with 15 – 26 light purple flowers; rachis 3 – 5 cm long; floral bracts reflexed, oblong-ovate, 3 – 5 mm, yellowish. Flower 14 – 16 mm long, not opening widely, sepals and petals purplish, lip purplish-white; pedicel and ovary 12 – 13 mm long. Dorsal sepal oblong-oblanceolate, 3-veined, 4.0 – 4.5 mm × ca. 2.0 mm. Lateral Sepals broad, obovate, 3-veined, 4.5 – 5.0 × 2.5 – 2.8 mm. Petals obovate-oblanceolate, 4.0 – 4.5 × ca. 2.0 mm. Lip spurred, 3-lobed, adnate to column foot; lateral lobes rounded, ca. 2 × 1.5 mm; mid lobe broadly obovate, 2.5 – 3.0 × ca. 2.5 mm, 5 veined, apex subtruncate; spur curved, cylindric, 15 – 17 × ca. 1 mm. Column stout ca. 1 × 1 mm. Anther cap hemispheric, shortly beaked ca. 1 mm in diameter; pollinia globose 2, attached by a common stipe to suborbicular viscidium. Fruit ellipsoid-cylindric. (Figure 1).

Notes and differentiation: Our studied plant show slight quantitative variation than the plants of Bhutan and China. This is probably due the geographical and climatic condition of the areas. However, overall main characteristics such as habit, inflorescence coloration of flower, spur length and other characters are almost similar. The other species under genus ‘Pendulorchis gaoligongensis’ distinctly differ from the species in discussion in having 14 – 25 cm long stem, 6 – 16 leaves which are 40 – 60 cm long, broadly ovate 2 – 3 mm long floral bracts, 5 – 18 cm long inflorescences which is with 18 – 41 flowers, flower with red colour lip and pollinia attached by a large suborbicular viscidium (Zhang et al., 2013). While in P. himalaica, the stems are 10 – 20 cm long, leaves are fewer in number (4 – 6) which are 20 – 55 cm long, floral bracts are oblong-ovate, 3 – 5 mm, inflorescences 4 – 13 cm long which is with 15 – 26 flowers, flower are purplish with purplish-white colour lip and pollinia attached by a comparatively smaller suborbicular viscidium.

Flowering & Fruiting: September – December.

Habitat: Four populations (each with 4 – 6 plants) were observed in a subtropical broad leaved forest spreaded in an area of about 0.5 sq. km. Based on previous and present report it appears this species prefer to grow in comparatively cool places at elevation of ca. 1750 – 2300 m.

Specimen examined: Nagaland, Tuensang district, Melangkiur Village, 26°05’24.5″ N 94°50’12.6″E, alt. 1790 m, 28.11.2014, H. Y. Jakha and S. Dey SDNU 467 (ASSAM).

Other specimen examined: Arunachal Pradesh, Kameng, Salari forests, alt. 2230 m, 28.09.1964, J. Joseph 40360 (ASSAM).

Distribution: India, Myanmar, China and Bhutan (Zhang et al., 2013; Xinqi & Wood, 2009; Pearce & Cribb, 2002; Kumar & Manilal, 1994; Kurzweil et al., 2014).

Acknowledgements
The authors (SD, HYJ) are thankful to the University Grants Commission, Govt. of India, New Delhi for financial assistance; to the Head, Department of Botany, Nagaland University, Nagaland for encouragement. Two of us (SKS & DV) are thankful to Director, BSI, Kolkata and H.O.O., Botanical Survey of India, BSI, Eastern Regional Centre, Shillong for facilities and encouragements.

References

Deori, N.C. and Das, G.C. 1976. Notes on rare orchids from North-eastern India –II. Bulletin of Botanical Survey of India 18(1-4): 233-235.

Kurzweil, H., Lwin, S. Phelps, J. and Ormerod, P. 2014. A guide to orchids of Myanmar. Natural History Publications (Borneo) Sdn, Bhd. Taiwan.

Pearce, N.R. and Cribb, P.J. 2002. Flora of Bhutan, including a record of plants from Sikkim and Darjeeling. Vol. 3 part 3. Royal Botanic Garden
Edinburgh, Royal government of Bhutan.

Sathish Kumar, C. and Manilal, K.S. 1994. A Catalogue of Indian Orchids. Bishen Singh Mahendrapal Singh, Dehradun.

Sathish Kumar, C. and Suresh Kumar, P.C. 2005. An Orchid Digest of Manipur, Northeastern India. Rheedea 15(1): 1-70.

Xinqi, C. and Wood, J. J. 2009. Ascocentrum. In: Wu Z.Y., Raven P.H. (Eds.) Flora of China, Vol. 25. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis pp. 502-503.

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