On the occurrence of Memecylonclarkeanum Cogn. (Melastomataceae) - a vulnerable species from Nilgiris, Tamil Nadu, India

C. Udhayavani ¹ & V.S. Ramachandran ²

^1,2 Taxonomy & Floristic Lab,Department of Botany, Bharathiar University, Coimbatore, Tamil Nadu 641046, India

¹ c.udhayavani@gmail.com (corresponding author), ² vsrbotany@gmail.com

doi: http://dx.doi.org/10.11609/JoTT.o3638.4811-3

Editor: N.P. Balakrishnan,Retd. Botanical Survey of India, Coimbatore, India. Date of publication: 26 September 2013 (online & print)

Manuscript details: Ms # o3638 | Received 24 May 2013 | Final received 02 September 2013 | Finally accepted 07 September 2013

Citation: C. Udhayavani & V.S. Ramachandran (2013). On the occurrence of Memecylon clarkeanum Cogn. (Melastomataceae) - a vulnerable species from Nilgiris, Tamil Nadu, India. Journal of Threatened Taxa 5(13): 4811–4813; http://dx.doi.org/10.11609/JoTT.o3638.4811-3

Copyright: © Udhayavani & Ramachandran 2013. Creative Commons Attribution 3.0 UnportedLicense. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

Funding: Self funded.

Competing Interest:Authors declare no competing interest.

Acknowledgements: The authors wish to thank Dr. S. Manian, Professor and Head, Department of Botany, BharathiarUniversity, Coimbatore for providing necessary facilities to carry out the research work in the department. The senior author is grateful to Prof. M.B. Vishwanathan, Department of Plant Science, Bharathidasan University, Tiruchirappalli for his help in identification.

The publication of this article is supported by the Critical Ecosystem Partnership Fund (CEPF), a joint initiative of l’Agence Française de Développement, Conservation International, the European Commission, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank.

For figure, images -- click here

The genus MemecylonL. (Melastomataceae) is widely distributed in the old world tropics and consists of ca. 250 species in the world (Mabberley2008; Bremer 1979, 1987). They are generally small trees or shrubs, mostly occurring in the understoreyof evergreen forests. Clarke (1879) reported 40 species from erstwhile British India. Out of these, Gamble (1919) reported 18 species from Madras Presidency and Cooke (1901) reported five species from Bombay Presidency in peninsular India. Vivekananthan (1983) recorded 16 species from Tamil Nadu. Sasidharan(2004) recorded 18 species from the adjoining state of Kerala. Recent enumeration reveals that 39 taxa of this genus are now known from India, of which 21 are endemics (Murugan & Gopalan 2006). In India, the Western Ghats is the majorcentre of diversity with 27 species, including 20 endemics confined to this ‘hotspot’ of biodiversity (Mohananet al. 2001; Viswanathan & Manikandan2001; Kumar et al. 2003; Manickam et al. 2007; Sivu et al. 2012).

While working on the floristic studies on the Gudalur and Pandalur taluks of Nilgiri District in Tamil Nadu, the authors could collect an interesting plant specimen of Memecylon L. from Devala, NilgiriDistrict (Fig. 1, Images 1,2). The specimen was critically studied and various characteristic features were examined. There was no match with any known species from Tamil Nadu. After further scrutiny of the specimen as well as the available literature, it was identified as Memecylon clarkeanum Cogn. This species was so far known as endemic to Sri Lanka, until Sivu et al. (2012) reported it from Wyanad, Kozhikode, Malappuramand Palakkad districts of Kerala. The present collection of this rare species from Tamil Nadu forms a new record for Tamil Nadu and it further strengthens the phytogeographicaffinities of Sri Lanka and peninsular India. The detailed description, phenology, distribution along with an illustration are also provided to facilitate easy identification of this plant. The specimen cited is deposited in the BharathiarUniversity Herbarium (BU 5325), Department of Botany, BharathiarUniversity, Coimbatore, Tamil Nadu for future reference (Image 3).

Memecylon clarkeanum Cogn. (Fig. 1, Image 1)

in DC., Mon. Phan. 7: 1141. 1891;Trimen, Handb. Fl. Ceylon 2: 217. 1894; Bremer, Opera Bot. 50:24. 1979; Dassanayake & Fosberg, A Revised Handb. Fl. Ceylon 6: 227.1987; Sivu et al., Taiwania, 57(3): 327-330. 2012. Memecylon heyneanum Benth. in Wall. ex Wight & Arn. var. latifoliaClarke in Hook. f., Fl. Brit. India 2: 560. 1879.

A large shrub, up to 3m high. Stems and branchlets subterete; bark brownish-grey, fissured. Leaves opposite; petiole stout, 7–9 mm long; elliptic to lanceolate, widest below the middle, 6–12×2.5–5 cm, cuneateat base, slightly revolute along margins, acute to acuminate at apex, glossy above, pale beneath, midrib with indistinct intramarginaland lateral veins, drying dark green on both sides; foliar sclereids filiform. Inflorescence a fascicle, congested on the leaf axils and at leafless nodes; pedicels absent or shorter than the receptacle; bracts ovate-lanceolate, ca. 1.5mm long, light green. Flower ca. 4mm across, pale blue; buds acute. Calyx campanulate or cup-shaped, ca. 2.5mm across, truncate and often with four shallow slits, yellowish; disc smooth or shallowly striate. Petals four, broadly elliptic-obovate, shortly clawed at the base, acute at apex, 2×2.2 mm, pale blue. Stamens eight, equal, filaments slender, ca. 5.5mm long, yellowish-white, anthers curved, ca. 2mm long. Ovary unilocular, ca. 11 ovules, placentation free-central, style subulate, ca. 5mm long, stigma simple. Fruitsglobose, berry, 0.8–1 mm across with persistent calyx, yellowish-green; seed 1.

Specimen examined: BU 5325, 01.iv.2013, Devala, Nilgiri District, Tamil Nadu, India, coll. C. Udhayavani.

Flowering and Fruiting: November–May.

Distribution: India (Kerala and Tamil Nadu) and Sri Lanka.

Ecology: It was collected from the degraded forest area of Devala near tea plantations. Only two individuals were observed in the study area.

Associated species: Achyranthes aspera L., Polygonum chinense L., Artocarpus heterophyllus Lam., Urena lobata L., Aporosa lindleyana (Wight) Baill., Strobilanthes sp.

Conservation status: Vulnerable (IUCN 2012).

Notes: In the study area only two individuals were noticed. Since they occur near tea plantations, there would be severe threats from biotic interference. Hence these two individual plants are to be protected by the forest department.

References

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