Sistotrema
Sistotrema
Main page
860607

Sistotrema

logo
Community Hub0 subscribers
What are your thoughts?
Be the first to start a discussion here.
Be the first to start a discussion here.
Sistotrema

Sistotrema is a genus of fungi in the family Hydnaceae. The genus contains at least 55 species and has a worldwide distribution. The type species is Sistotrema confluens Pers. (1794).

The genus includes both terricolous and lignicolous species. Most species of Sistotrema are white rotting saprotrophs which often occur on highly decayed wood and on bark of attached, dead branches, but endophytic and ectomycorrhizal nutritional modes also exist in some species. Sistotrema confluens is ectomycorrhizal and S. alboluteum, S. muscicola and S. albopallescens are suspected of being so. In the genus only S. confluens and S. subconfluens are known to grow on soil.

Basidiocarps of Sistotrema generally start spore production very early.

Only the type species S. confluens, and S. subconfluens, form stipitate basidiocarps while all other species in the genus form resupinate, corticioid basidiocarps. There is large variation in the configuration of the hymenophore, which can range from strictly hydnoid to poroid, but the dominating type of hymenophore is smooth. Basidiocarps are soft and membranaceous or ceraceous, and can be pelliculose or waxy.

The hyphal system is monomitic and consist of generative hyphae with clamps, which are often ampullate. The subicular hyphae have characteristically oily contents and the septa have perforate parenthesomes.

Basidia are urniform and usually have 6-8 sterigmata, but some species are known to mainly have 2-4 sterigmata. Basidiospores are small, smooth, hyaline and ranging between globose, ellipsoid, oblong or allantoid in shape. They are thin-walled and non-cyanophilous, non-amyloid and non-dextrinoid.

Cystidia are mostly absent but some species have enclosed gloeocystidia or projecting leptocystidia.

Sistotrema has been considered a well delimited genus by the urniform basidia, the number of sterigmata and the oily contents of the hyphae. Phylogenetic analyses during the 21st century have, however, shown that Sistotrema is a polyphyletic genus. It is closely related to the genera Hydnum, Clavulina, and Membranomyces. The mycorrhizal species of Sistotrema form a monophyletic group with the mycorrhizal genus Hydnum, while the remaining saprophytic species in the genus have been suggested by Larsson (2007) to be distributed over several other genera.

See all
User Avatar
No comments yet.