Basidiome development of Xeromphalina campanella (Tricholomatales, Basidiomycetes)

The agaricoid Hymenomycete Xeromphalina campanella is exocarpic, apertopileate and amphiblemate. Metablemas develop separately on the pileus and on the stipe, but they do not form any kind of veil. The pileoblema becomes a gelatinous pileipellis, and the cauloblema forms a hairy coating on the lower part of the stipe of the mature basidiomes. The hymenophoral trama is bidirectional in the gill rudiments, but becomes more physalo-irregular at maturity and contains many narrow hyphae with smooth or incrusted walls. The context of the stipe resembles a sarcodimitic structure, but the thin-walled inflated cells are rarely fusiform, although they are frequently gradually narrowed at one end. Between the physalohyphae, narrow, incrusted hyphae and ramified connective hyphae occur in the stipe and in the pileus context. The hyphae of the pileus of a young basidiome contain granular deposits of glycogen.