Taxonomic studies of Japanese boletes II. The genus Boletinus

摘要

Documented records on three species of Boletinus known in Japan are presented with their descriptions and illustrations. They are: B. asiaticus, B. cavipes, and B. paluster. A key to the Japanese species is also given. This is the second report of theseries, in which the genus Boletinus is treated. In the first report (Nagasawa, 2001) members of the genera Boletinellus, Gyrodon, and Gyroporus were reported. The genus Boletinus is a representative member of fleshy fungi in the larch forest and distributes around the North Pole within the range of the conifer genus Larix. In the strict sense (Singer, 1986; Sutara, 1987; Jarosch, 2001) it would comprises four species in the world, viz. B. asiaticus Singer, B. cavipes (Opat.) Kalchbr., B. ochraceoroseus Snell, and B. paluster (Peck) Peck. Of these there have been known in Japan three species except for B. ochraceoroseus (Nagasawa, 1989, 1997). However, it seems that their distribution and morphological variation in Japan are still poorly known with few documented records. This report describes and illustrates the Japanese members based on recent collections deposited in the herbarium of the Tottori Mycological Institute (TMI), and presents additional data on the morphology and the distribution for each species.