A reinvestigation into the taxonomic status of Riccia himalayensis and Riccia discolor based on scanning electron microscopic and chemotaxonomical studies

Abstract

Riccia himalayensis St. (Ms.) Kashyap is a common species found in the Himalayas from the foot of the mountains to an altitude of 2743 m. Ricciadiscolor Lehm. et Lindb. on the other hand, is the common and most widely distributed monsoon species, that has been reported from both the western and eastern Himalayas, as well as from the plains of Assam, west Bengal, Madhya Pradesh, south India, etc. Dispute still exists regarding the taxonomic status of R. himalayensis, which is considered a synonym of R. discolor by some taxonomists, according to whom R. himalayensis has no specific status. This has led to a lot of errors in interpreting R. discolor. On the other hand many authors have considered R. himalayensis to be a composite species of R. discolor, R. billardieri and R. gangetica.The present investigation was aimed to reinvestigate the taxonomic status of R. himalayensis and R. discolor based on morphological analysis of thallus and spore surface by light microscope and scanning electron microscopy (SEM) studies and biochemical analyses of the protein profile by SDS‐PAGE. Results reveal that although the two species share certain common morphological features, they are two distinct species chemotaxonomically.