Classification of The Genus Coixl. (Maydeae)

The genus Coix is comprised of nine species. Different taxonomic treatments of the genus have no unanimity on the number of species raised or the criteria chosen for the purpose. The characters utilized were habit and habitat differences, glands on leaf sheath and surface, auricle, suture separating leaf sheath and blade, leaf width, nature of staminate inflorescence and width of lower glume of its spikelet, false fruit size, colour, texture and shape. All these characters are found to be inconsistent and show variations within species and therefore perceived unreliable for classification purposes. Only two characters, rhizome (presence vs absence) and false fruit shape (pyriform vs ovoid, globose, cylindrical etc.) are consistent in a species. Besides, there are differences among the species in chromosome number and size as well as intragenomic pairing in haploid state. Morphological description for all the species is given and a key for distinction of the species is provided using morphological as well as chromosome characteristics.