Habenaria richardiana (Orchidaceae), a littleknown endemic orchid from Nilgiri Biosphere

Reserve (India)

V. Ravichandran1*, M. Manikandan2 & C. Murugan1

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1Botanical Survey of India, Southern Regional centre, TNAU campus, Coimbatore – 641 003.Tamil Nadu, India2Department of Botany, Government Arts College, Ooty – 643 002, Tamil Nadu, India*corresponding author: ravichandran725@gmail.com________________________________

AbstractHabenaria richardiana Wight is a little known orchid species endemic toNilgiri Biosphere Reserve, in the Western Ghats, Tamil Nadu (India). Aspecimen has been collected from its type locality after 48 years. A shortdescription and colour photographs are provided here for easyidentification and further collection.

RésuméHabenaria richardiana Wight est une orchidée peu connue, endémique de laRéserve Nalgiri Biosphere Reserve, dans les Western Ghats, Tamil Nadu,Inde. Un spécimen a été découvert et collecté dans la localité type, 48 ansaprès la dernière collecte. Nous proposons ici une courte descriptionmorphologique assortie de photographies pour en faciliter l'identification,en vue de futures collectes.

Keywords: Anamalais, Fischer, Gamble, ICN, typification.Mots clés : Anamalais, Fischer, Gamble, ICN, typification.

Manuscrit reçu le 15/11/2018 Article mis en ligne le 14/02/2019 – pp. 25-30

IntroductionHabenaria Willdenow (1805: 44) (Orchidaceae) is a major genus consistingof about 876 taxa (Govaerts et al., 2018; Batista et. al., 2013; Prasad & Venu,2015) dispersed through the tropical and subtropical regions of the Old andNew Worlds (Pridgeon et al., 2001) with centres of diversity in Brazil,Southern and Central Africa and East Asia (Batista et al., 2013). Of the totalnumber of species recorded in India (ca 72), 45 species are found in theWestern Ghats (Kumar et al., 2016) and 16 species are reported from Nilgirihills (Joseph, 1987). Among them, 30 species are endemic to India and 21species are endemic to the Western Ghats (Misra, 2007; Sathish Kumar &Manilal, 1994; Prasad & Venu, 2015; Kumar et al., 2016).During the systematic studies on the plants endemic to the NilgiriBiosphere Reserve, the senior author collected an interesting Habenariaspecies in high altitude grasslands of the Blue Mountains (Nilgiri). Afterdetailed studies of literature (Wight, 1852; Hooker, 1890; Fischer, 1928;Joseph, 1987), and of herbarium specimens, it was identified as Habenariarichardiana Wight (1852: 14).This species was first collected by Robert Wight. Based on this collection hedescribed this species in 1851 in his work Icones Plantarum Indiae Orientalis.After that, three collections are available at MH: one was collected in 1883by an unknown collector from Doddabetta, Nilgiris without collectionnumber; a second one was collected in the same year by Gamble(Collection Number 13098) from Lovmon Peak, also in Nilgiris; howeverthe latter was first identified by Gamble as H. decipiens Wight (1852: 14)now considered as a synonym of H. longicornu Lindley (1835: 322); later itwas correctly identified as H. richardiana by C.E.C. Fischer. The thirdspecimen was collected by Vajravelu from Viewpoint, Kodanad, Nilgiris in1970. Thereafter it has not been collected nor reported from the Nilgiris.Robert Wight mentioned its occurrence in Anamalais but it is uncertainbecause there is no representative collection from that place till now. Thepresent collection represents the rediscovery of the species after a lapse of48 years, from the type locality.There are two herbarium sheets at Kew collected by Robert Wight from theNilgiris for the name Habenaria richardiana. The locality name (Neilgherries,Nilgiris) is mentioned in the protologue. From the two herbarium sheets(K000247430! & K000247431!), it is clear that each of them may be theoriginal material used by Robert Wight while describing this species. In

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accordance with to the Article 9.3 & 9.4 (ICN, 2018), the first material fromthe left hand side present on the sheet K000247430 is here designated as alectotype because it matches well with the protologue and it contains allthe parts viz. tuber to the flowers (Fig. 1).

Taxonomic treatmentHabenaria richardiana Wight, Icones Plantarum Indiae Orientalis t. 1713(1852); Fischer, Flora of Presidency of Madras: 1470 (1928 - reprint edition 3:1027 [1957]); Joseph, Orchids of Nilgiris 87 (1987). Type: India, Tamil Nadu:Nilgiri District, s.n. s.d. Robert Wight (lectotype K000247430, first materialfrom the left hand side, here designated; isolectotype K000247431, secondmaterial from the left hand side, here designated). (Fig.1).

Terrestrial herbs, up to 15-25 cm high, stem short, leafy at base. Tubers two,oblong, ca. 3 × 1 cm. Leaves alternate, simple, 4-6 × 1-1.5 cm, sessile, ovate-lanceolate, membranous sheathing at base, apex acute-acuminate,channelled, leaf margin entire. Inflorescence 5-15 cm, loose spike 6-8 cmlong, 8-12 flowered. Flowers white, 2 cm diam., bisexual, zygomorphic.Bracts ca. 2 × 0.5 cm, ovate-lanceolate, apex acuminate, shorter than theovary. Dorsal sepal ca 0.6 × 0.4 cm, ovate-cordate, cucullate, apexacuminate, 3-5 nerved, margin entire. Lateral sepals 0.7-0.9 × 0.5-0.6 cm,slightly pubescent, oblong-lanceolate, spreading, apex acuminate andreflexed, margin entire. Petals 0.5-0.7 × 0.3-0.5 cm, ovate-lanceolate, apexobtuse, margin slightly ciliate. Lip 0.6-0.9 × 0.3-0.5 cm, fan shaped, trilobed,side lobes fimbriated, middle lobe slightly longer and sometimes smallerthan side lobes; spur 2.5-3 cm, longer than the ovary, with an upper partwhite and a lower part green, cylindrical, clavate at apex, decurved. Ovaryca 1.5 cm long, pendulous (Fig.1).

Flowering: August to October.

Habitat: Habenaria richardiana is restricted to high altitude grasslands above2000 masl.

Specimen examined: India. Tamil Nadu: Nilgiri district, s.d. Robert Wight,K000247430 & K000247431 (K!); J.S. Gamble 13098, Oct 1883(MH00050067!); Doddabetta, 29 Oct 1883, s.coll. 50769 (MH00050066!); Viewpoint, Koadanad, 12 Sep 1970, E. Vajravelu 36860 (MH00050068!); Valleyview point, N 11°23.060’ E 076°43.132’, 2151 m 16 Sep 2018 V.Ravichandran 139186 (MH!).

Lectotypification of Habenaria richardiana – V. Ravichandran et al.

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Opposite page

Fig. 1. Habenaria richardiana WightA: Habitat; B: Habit; C: Inflorescence (close up); D: Flower (close up);

E. Lectotype K000247430 [© Board of Trustees Royal Botanical Garden, Kew]

Conservation Status. The species is restricted to high altitude grasslands ofNilgiri district of Tamil Nadu state. The senior author has made extensiveexploration in Nilgiri Biosphere Reserve during the years 2012-2018 andlocated a single population with less than twenty individuals. Before this,we can register only three collections from Nilgiris in the year 1850 (RobertWight), 1883 (Gamble) and 1970 (Vajravelu). During the documentation ofOrchids of Nilgiris by Joseph (1987) the species could not be collected.Based on the study of literature, herbarium data and field observationsfrom 2012 to 2018, Habenaria richardiana is currently categorized asCritically Endangered: D (IUCN 2012).

AcknowledgmentsAuthors are grateful to Dr. Paramjith Singh, Director, Botanical Survey ofIndia, Kolkata for facilities and support and Tamil Nadu forest departmentfor permission and essential helps during the field explorations. We arealso indebted to the Curators of K for information and images ofspecimens.

Literature CitedBatista, J.A.N., S.B. Karina, W.F. Marina de Faria, P. Karina, J.R. Aline, A.S.Gerardo & C. van den Berg, 2013. Molecular phylogenetics of the species-rich genus Habenaria (Orchidaceae) in the New World based on nuclear andplastid DNA sequences. Molecular Phylogenetics and Evolution 67: 95-109.Fischer, C.E.C., 1928. Habenaria. In J.S. Gamble, Flora of The Presidency ofMadras, Vol. 3. Adlard & Son, London 3: 1027.Govaerts, R., J. Pfahl, M.A. Campacci, B.D. Holland, H. Tigges, J. Shaw, P.Cribb, A. George, K. Kreuz & J. Wood, 2018. World Checklist ofOrchidaceae. The Board of Trustees of the Royal Botanic Gardens, Kew.http://apps.kew.org/wcsp (retrieved on 25 Sep 2018).

Lectotypification of Habenaria richardiana – V. Ravichandran et al.

Hooker, J.D., 1890. Habenaria In Hooker, Flora of British India, Vol.6: 139.London, L. Reeve & co.IUCN, 2012. IUCN Red List Categories and Criteria: Version 3.1. Secondedition. International Union for Conservation of Nature and NaturalResources, Gland and Cambridge.Joseph, J., 1987. Orchids of Nilgiris. Botanical Survey of India, Howrah. 66pp.Kumar, P., K.M. Prabhukumar, T.K. Nirmesh, V.B. Sreekumar, V.S.Hareesh, & I. Balachandran, 2016. Habenaria sahyadrica (Orchidaceae,Orchideae) a new species from the Western Ghats (India) with critical noteson allied taxa. Phytotaxa 244 (2): 196-200.Lindley, J., 1828. In Wallich catalogue, Numerical list of dried specimens ofplants in the Museum of the Honl. East India Company. n. 7027.Misra, S., 2007. Orchids of India, a glimpse. Bishen Singh Mahendra PalSingh, Dehra Dun. 17 pp.Prasad, K. & P. Venu, 2015. A New Generic Status to Section Plectoglossa(Orchidaceae: Habenaria). Rheedea 25(2): 86-93.Pridgeon, A.M., P. J.Cribb, M.W. Chase & F. N. Rasmussen, 2001. GeneraOrchidacearum Vol. 2. Orchidoideae, Part 1. Oxford University Press Inc.,New York.Sathish Kumar, C. & K. S. Manilal, 1994. A Catalogue of Indian Orchids.Bishen Singh Mahendra Pal Singh, Dehra Dun. 24 pp.Turland, N. J., J. H. Wiersema, F. R. Barrie, W. Greuter, D. L. Hawksworth,P. S. Herendeen, S. Knapp, W.-H. Kusber, D.-Z. Li, K. Marhold, T. W. May,J. McNeill, A. M. Monro, J. Prado, M. J. Price, & G. F. Smith (eds.), 2018.International Code of Nomenclature for algae, fungi, and plants (ShenzhenCode) adopted by the Nineteenth International Botanical CongressShenzhen, China, July 2017. Regnum Vegetabile 159. Glashütten: KoeltzBotanical Books. DOI https://doi.org/10.12705/Code.2018 6.Wight, R., 1852. Icones Plantarum Indiae Orientalis, Vol. 5: 14 (t. 1713). J.B.Pharoach, Madras.Willdenow, C.L., 1805. Species plantarum editio quarta. Nauk, Berlin, 544pp.

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