The Meruliaceae of Russia. I. Bjerkandera

Abstract

This paper opens a taxonomical survey on the genera of Meruliaceae (Polyporales, Basidiomycota) presented in Russian mycobiota. All the meruliaceous fungi represent an obligate component of heterotrophic block of forest ecosystems and considerable demanded biotechnological resource. The purpose of the present elaboration is a revision of East European and North Asian material on Bjerkandera genus highlighting its species’ and intraspecific morphological variability and substrate specialization. The macroscopic descriptions are based on a study of fresh and dried specimens. The material of the herbaria of Komarov Botanical Institute (St. Petersburg, LE) and Institute of Zoology and Botany of Estonian Agricultural University (TAA) is studied. Micromorphological analysis is included the hyphal system revealing, the hyphae, basidia/basidiospores morphometry, and microchemical tests of the structures in question. The genus Bjerkandera is accepted in its original Karstenian sense, although the concepts by Pilat, Corner, Pouzar, and Zmitrovich et al. were discussed. The genus is characterized by two-layered context with rather loose tomentum and dense layer above the hymenophore, monomitic to pseudodimitic hyphal system, clamped generative hyphae, and ellipsoid-cylindrical basidiospores not staining in Cotton blue and Melzer’s reagent. Only two species, Bjerkandera adusta and B. fumosa were recognized in the genus, and a possible position of B. subsimulans and B. terebrans was discussed, too. The polymorphism of B. adusta is exhaustively presented and the form tegumentosa was epitypified and described. The polymorphism of B. fumosa is also presented, and the form flavipora was correctly published and epitypified. The relationships between two species are discussed and the key for species delimitation is presented here. Distributional patterns are presented for both species as well as their substrate range. The substrates of B. adusta and B. fumosa in old-growth arboreta of Saint Petersburg are presented.