Russula in Himalaya 2: Four new taxa

摘要

Russula mayawatiana, R. dhakuriana, R. appendiculata and R. puellaris var. atrii are proposed here as new taxa. Phylogenetic positions within the genus Russula are supported by macroscopic and microscopic characters as well as rDNA sequences in the ITS gene region. Critical taxonomic studies based on the morphological and anatomical characters of the genus Russula from Himalaya have been carried out by different authors (Wading & Gregory 1980, Saini et al. 1982, Atri & Saini 1989, Atri et al. 1991, Atri et al. 1992, Atri et al. 1993, Saini et al. 1993, Atri et al. 1994, Shajahan & Samajpati 1995, Atri et al. 1997, Rawla 2001, Das & Sharma 2003, Das 2005, Das et al. 2006) for the last twenty five years. The flora of the large genus Russula from the world over is creating confusion among taxonomists about the proper taxonomic circumscription of species and their placement in the infrageneric classification schemes. Moreover, the morphological and anatomical characters are sometimes not sufficient tocomparatively analyse the taxa or establish them as undescribed (new). To eliminate this confusion, efforts have been initiated by a few workers (Miller et al. 2001, Miller & Buyck 2002) to use DNA sequencing to support comparative taxonomic approaches.During a number of macrof ungal surveys in Western and North-western Himalaya, the authors gathered a large number of specimens which after thorough morphological and microscopic studies revealed numerous undescribed taxa. Further, DNA sequencing of fivetaxa also confirmed their status as new to science. Four of them, viz., R. mayawatiana, R. dhakuriana, R. appendiculata and R. puellaris var. atrii are described and illustrated below, whereas, the fifth one i.e. R. mukteshwarica has been submitted (Daset al. 2006) for publication. The molecular tree supporting circumscription of these taxa as new is also provided (Fig. 5, p. 214).