Murdannia saddlepeakensis (Commelinaceae) – a new species from Andaman and Nicobar Islands, India

Abstract Murdannia saddlepeakensis (Commelinaceae), a new species from the Andaman and Nicobar Islands, India, is described and illustrated. The new species is remarkable for its narrowly linear leaves, two fertile stamens, single seeded locule and scorbiculate seeds.


Introduction
Th e genus Murdannia is represented by 54 species (Govaerts and Faden 2004), of which 27 taxa are reported from India (modifi ed after Karthikeyan et al. 1989). Th ree new taxa viz., M. fadeniana Nampy & Joby (Nampy and Joby 2003), M. satheeshiana Joby et al. (Joby et al. 2011) and M. brownii  have been described during the last decade. In addition, M . striatipetala Faden has been rediscovered from India . Th e Western Ghats of India alone comprises twenty-two species and serve as a major centre of diversifi cation for Murdannia .
Th e Andaman and Nicobar Islands harbour luxuriant lowland rainforests besides wetlands, mangroves and coral reefs. Th e fl oral elements of these Islands often show close affi nity with that of Indonesia, Malaysia, Myanmar, Th ailand and Sri Lanka. Saddle Peak National Park which is located in the North Andaman Islands harbours unique stunted evergreen vegetation that is found only in restricted localities of the Andaman Islands (Rao 1986).

Murdannia saddlepeakensis
Distribution. Murdannia saddlepeakensis is so far only known from Saddle Peak National Park, North Andaman Islands, India.
Ecology Th e fi rst four species have more than two seeds per locule and rest four have two seeds per locule while M. saddlepeakensis has single seed per locule.
Murdannia saddlepeakensis closely resembles M. simplex but can be easily distinguished by its narrow linear leaves, terminal fl owering shoot in the basal rosette, glabrous leaf sheaths, single seeded locule, elliptic seed with scorbiculate surface. In addition, M. saddlepeakensis is restricted to northern Andaman Island whereas M. simplex is much more wide spread in Tropical Africa and Asia. M. gigantea with a terminal fl owering shoot also is similar to M. saddlepeakensis but diff ers in having thick, fi brous roots, broad leaves, three stamens and seeds with dorsal embryotega. M. saddlepeakensis can also be mistaken for the widespread M. loriformis in general. However, the presence of erect, terminal fl owering shoot and scorbiculate, single seeded locule along with anthesis by noon supports its distinctness. Pandey and Diwakar (2008)