Taxonomy and phylogeny in Lepiota sect. Stenosporae from China

Lepiota sect. Stenosporae (J.E. Lange) Kühner contains species with spurred or truncate basidiospores and pileus covering composed of adnate, ascending or erect long and slender elements. Seven species from southwestern, northeastern and southern China in this section have been identified, described and illustrated. Lepiota mandarina and L. subcastanea are described as new. Lepiota mandarina is characterized by densely orange red to brownish red squamules on pileus and stipe, subtriangular basidiospores with truncate bottom, narrowly clavate cheilocystidia and pileus covering a trichodermial palisade. Lepiota subcastanea has a pileus with yellow-brown to dark brown squamules, non-dextrinoid subtriangular basidiospores with a distinct sac-like spur, narrowly clavate or narrowly utriform cheilocystidia, and pileus covering a trichodermial palisade with short clavate elements. It is hypothesized that this section evolved from sect. Ovisporae subsect. Helveolinae. It also is speculated that subtriangular and spurred basidiospores have evolved from ellipsoidal basidiospores and that a trichodermial pileus covering composing long, erect elements and basal short, clavate elements might have evolved from a cutis or a trichoderm lacking such an under layer of short elements.