- Source: Exidia saccharina
Exidia saccharina is a species of fungus in the family Auriculariaceae. Basidiocarps (fruit bodies) are gelatinous, reddish brown, button-shaped at first then often coalescing and becoming irregularly effused. In the UK, it has the recommended English name of pine jelly. It grows on dead branches of conifers and is known from Europe, North America, and northern Asia.
Taxonomy
The species was first described in 1805 from Germany as Tremella spiculosa var. saccharina by mycologists Johannes Baptista von Albertini and Lewis David de Schweinitz and raised to species level in Exidia by Elias Magnus Fries in 1822. Recent molecular research, based on cladistic analysis of DNA sequences, has shown that the species is distinct. Exidia subrepanda, originally described from Finland on spruce (Picea), is considered a synonym.
Description
The basidiocarps of E. saccharina are orange-brown, gelatinous, button-shaped at first but sometimes coalescing to form effused, irregular, often ridged masses up to 10 cm across. They become leathery, dark, and shriveled when dry.
= Microscopic characters
=The translucent hyphae are 0.5–2.5 μm in diameter, monomitic, branched, thin-walled, and form clamp connections. Hyphae frequently form anastomoses. Basidia are typically 13 to 15.5 μm long, elliptical, and consist of four longitudinally septate cells. Basidiospores are allantoid (sausage shaped), 10 to 14 by 3 to 4.5 μm, with thin, smooth walls.
= Similar species
=Fruit bodies of Exidia subsaccharina (known from France and England) also occur on conifers and are not distinguishable in the field, but have larger basidia and spores (12.5 to 17.5 by 4 to 5.5 μm).
Distribution and habitat
Exidia saccharina is most common in Scandinavia, but can also be found elsewhere in Europe, in northern parts of Asia, and in North America.
Exidia saccharina grows only on dead conifers, including species of Abies, Larix, Picea, and most commonly Pinus. It seems to grow most preferentially on Pinus strobus. In its anamorphic (asexual) state, it has been found in association with bark beetles.
Conservation status
Exidia saccharina is currently listed on the register of protected and endangered fungi of Poland.
