Dimorphocalyx

Abstract: Tirunelveli hills of Tamil Nadu harbour over 2000 species of plants, of which 25% are endemic and 3% are under various categories of threat. An ethnobotanical survey was carried out among the tribal people (kani/kanikaran) inhabiting the Tirunelveli hills of Tamil Nadu and the study revealed that, they are using more than 350 plants to prepare medicine, of which 8% (30 species) are belongs to the family Euphorbiaceae and it is consistent with the claim by the floristic diversity of this family. In floristic survey, Euphorbiaceae is one of the best-represented families in Tirunelveli hills of Tamil Nadu with 124 species of plants belonging to 34 genera and ranks third followed by Leguminosae and Poaceae in terms of number of species. The largest genera in Euphorbiaceae are Phyllanthus , Euphorbia and Mallotus , each with 21, 18 and 11 species respectively. Euphorbiaceae includes more number of endemic plants with 31 sps. and the genus Phyllanthus includes five endemic species; Blachia , Drypetes , Euphorbia , Glochidion and Mallotus with three species. The plants such as Blachia calycina Benth., Blachia umbellata Baill., Dimorphocalyx lawianus (M.Arg.) Hk.f., Mallotus stenanthus M.Arg., Phyllanthus baillonianus M.Arg. and Baccaurea courtallensis M.Arg. are identified as endemic medicinal plants. Majority of the plants present in these hills are rapidly threatened by anthropogenic activities due to several pilgrim and tourist places within the forest area. Its biodiversity is vulnerable due to different factors, and its conservation should be paid enormous attention by involving the local communities and forest representatives in preservation and conservation aspects. Key words: Tirunelveli hills, Endemism, Euphorbiaceae, Medicinal plants, Threat status --- 1 Division of Biodiversity and Biotechnology, Department of Botany, Pachaiyappa’s College, Chennai - 600030, Tamil Nadu, India; 2 Entomology Research Institute, Loyola college, Chennai – 600 034; Tamil Nadu, India --- Please Cite This Article As: M. Ayyanar and S. Ignacimuthu. 2010. Diversity, Conservation Status and Medicinal Plants of the Family Euphorbiaceae in Tirunelveli Hills, Southern India. J. Exp. Sci. 1(6):12-16.

Abstract: Dimorphocalyx, a small genus ranging from Sri Lanka to Indomalesia to Australia, has eight species in Malesia, of which one is here raised from variety to species level and another, endemic in the N Moluccas, is newly described. Dimorphocalyx murinus and – tentatively – D. loheri are synonymised with D. denticulatus, and D. luzoniensis is synonymised with D. malayanus. Dimorphocalyx cumingii is regarded as a species of Trigonostemon. The differences between Dimorphocalyx, Ostodes, Paracroton (formerly Fahrenheitia), and Trigonostemon are discussed.

Abstract: The variability of Ostodes paniculata var. paniculata, the only representative of the genus in Malesia, is described. The variety and the species have a disjunct distribution as they are found in India to Southern China and the Southeast Asian mainland, Sumatra and Java. The variability in leaf glands, domatia, sepals, and seeds shows geoclines. Depending on one’s view the genus has two more varieties or species, both more hairy and occurring from N Thailand to China or in China only. Their nomenclature is provided, as is the nomenclature of the many excluded species, once part of a larger generic concept of Ostodes, but now mainly part of Dimorphocalyx and Paracroton. Typical for Ostodes are the red latex, the ovate, rather large serrate leaf blades with basally two raised glands, the paniculate inflorescences with relatively large flowers with petals and many (nearly) free stamens, and the large woody fruits.

Abstract: A revision of the genusDimorphocalyx Thw. (Euphorbiaceae) for India and adjoining countries is presented. Three species and two varieties are recognised.Dimorphocalyx beddomei (Benth.) Airy Shaw is endemic to south India.Dimorphocalyx lawianus Hook. f., endemic to south India is reduced to a variety ofDimorphocalyx glabellus Thw.Dimorphocalyx dilipianus Balakr. and T Chakrab. is reduced to a synonym ofDimorphocalyx balakrishnanii T Chakrab. and Premanath, endemic to Andaman Islands. Keys to the taxa, taxonomic descriptions and illustrations are presented.