Sirobasidium

Sirobasidium is a genus of fungi in the order Tremellales. Basidiocarps are gelatinous and appear to be parasitic on ascomycetous fungi on wood. Microscopically they are distinguished by producing septate basidia in chains which give rise to deciduous sterigmata. Species are distributed worldwide.

Taxonomy

Sirobasidium was introduced in 1892 by Swedish mycologist Gustaf Lagerheim and French mycologist Narcisse [Théophile Patouillard|Narcisse Patouillard] for two fungi collected in Ecuador that possessed distinctive, catenulate, tremelloid basidia. Subsequent authors added further species with similar basidia.
Molecular research, based on cladistic analysis of DNA sequences, has shown that Sirobasidium may be polyphyletic, though this is based on a single culture that may be contaminated and requires further research.

Description

Fruit bodies are gelatinous and are variously pustular to foliose. Colours are typically reddish, yellow, or brown.

Microscopic characters

The basidia are "tremelloid" and catenulate, giving rise to fusiform sterigmata or epibasidia which detach from the basidia and then produce basidiospores. These spores are smooth, globose, and germinate by hyphal tube or yeast cells.

Habitat and distribution

Sirobasidium species are associated with and possibly parasitic on fungi in the Diatrypaceae growing on dead attached or fallen wood, including species of Eutypa, Eutypella, and Diatrype. As a group, Sirobasidium species occur worldwide, though individual species may have a more restricted distribution.