A NEW SPECIES OF Sonerila ( MELASTOMATACEAE ) FROM THE WESTERN GHATS-INDIA Sectional

A new species of Sonerila Roxburgh (Melastomataceae) is described and illustrated. Sonerila nayarana sp. nov. occurs in the Velliangiri hills, the Western Ghats in the Coimbatore District, Tamil Nadu, India. It seems most similar to Sonerila parameswaranii Ravikumar & Lakshmanan, 1999.


Introduction
Sonerila Roxburgh (Melastomataceae) occurs with c. 43 species from India and Sri Lanka to China and through Malesia to New Guinea (Lundin & Nordenstam, 2009;www.tropicos.org).It is well represented in Southern India.In Tamil Nadu there are about 23 species and 2 varieties (Nair & Henry, 1983;Giri & Nayar, 1985;Ravikumar, 1999).It is the only trimerous genus (except for the monotypic Stussenia Hansen and Lithobium Bong.) and the stamens are in one or rarely two whorls.

Remarks:
The species is present only during the South-west monsoon (August to September).Because the plants are so ephemeral and small, they are easily overlooked.We noticed only two wellseparated populations, each of not more than 5 plants, one from under rocks and another one from rock crevices.Plants prostrate-procumbent. Shrub up to 1.5 m high.
Leaves oblique at base, acuminate at apex.
Leaves cordate or rounded or rarely truncate at base, acute-very shortly acuminate or rarely obtuse or rounded at apex.Leaves ciliate at margins.
Leaves with ciliate at serrature only.Leaves pinninerved.
Petiole up to 6 cm long, densely villous.Petiole up to 2.5 cm long, few hairy at the vicinity of leaf base only.Pedicel up to 1.8 cm long.

Ecology:
Rarely found along the crevices of moist rocks in open grasslands at about 1700 m a.s.l. on western slopes.It is always associated with species such as Eriocaulon spp.Impatiens clavicornu, I. bromoides, etc.Flowering & Fruiting: August-September.

Table 1 :
The major differences between the species