Type studys on Japanese species of Lactarius described by S. Imai

Wang X. H. & Liu P. G. (2010) Type study on Japanese species of Lactarius described by S. Imai.

Sydowia 62 (2): 225-335

Holotype material and/or authentic collections of five Japanese taxa (deposited in the herbarium SAPA), described by S. Imai in 1935 were re-examined, viz. Lactarius akanensis, L. avellaneus, L. deliciosus f. laeticolor, L. deliciosus f. virescens, and L. flavidulus. For L. deliciosus f. laeticolor a lectotype was designated. The neotypification of L. deliciosus f. virescens is pending because no original material is available. The morphological analysis shows that the five enumerated taxa belong to Lactarius subgen. Piperites. Lactarius akanensis is a member of the L. trivialis-complex. Lactarius avellaneus is characterized by an ixolattice with incrustations in the pileipellis and the latex staining yellow. Lactarius flavidulus belongs to Lactarius subgen. Piperites sect. Zonarii, in which it is remarkable due to the gray-greenish discolouration of the latex and lamellae. Detailed macromorphological and micromorphological descriptions and illustrations are presented.

Key words: Japan, lectotypification, Russulaceae, Taxonomy.