Mycena Sanguinolenta

''Mycena sanguinolenta'', commonly known as the bleeding bonnet, the smaller bleeding Mycena, or the terrestrial bleeding Mycena, is a species of mushroom in the family Mycenaceae. It is a common and widely distributed species, and has been found in North America, Europe, Australia, and Asia. The fungus produces reddish-brown to reddish-purple fruit bodies with conic to bell-shaped caps up to wide held by slender stipes up to high. When fresh, the fruit bodies will "bleed" a dark reddish-purple sap. The similar ''Mycena haematopus'' is larger, and grows on decaying wood, usually in clumps. ''M. sanguinolenta'' contains alkaloid pigments that are unique to the species, may produce an antifungal compound, and is bioluminescent. The edibility of the mushroom has not been determined.

Taxonomy

First called ''Agaricus sanguinolentus'' by Johannes Baptista von Albertini, the species was transferred to the genus ''Mycena'' in 1871 by German Paul Kummer, when he raised many of Fries' "tribes" to the rank of genus. The specific epithet is derived from the Latin word ''sanguinolentus'' and means "bloody". It is commonly known as the "bleeding bonnet" the "smaller bleeding Mycena", or the "terrestrial bleeding Mycena".

The fungus is classified in the section ''Lactipedes'' along with other latex-producing species.Smith 1947, pp. 132–33. A molecular phylogenetic analysis of several dozen European ''Mycena'' species suggests that ''M. sanguinolenta'' is closely related to . Other phylogenically related species include and .

Description

The cap of ''M. sanguinolenta'' is either convex or conic when young, with its margin pressed against the stipe. As it expands, it becomes broadly convex or bell-shaped, ultimately reaching a diameter of . The surface is initially covered with a dense whitish-grayish coating or powder that is produced by delicate microscopic cells, but these cells soon collapse and disappear, leaving the surface naked and smooth. The surface is moist with an opaque margin that soon developing furrows. The cap color is variable but always some shade of bright or dull reddish brown with a dull grayish-brown margin. The flesh is thin, not very fragile, sordid reddish, and exudes a reddish latex when cut. The odor and taste are not distinctive.

The gills are adnate or slightly toothed, and well-spaced. They are narrow to moderately broad, sordid reddish to grayish, with even edges that are dark reddish brown. The stipe is long, 1–1.5 mm thick, equal in width throughout, and fragile. The base of the stipe is covered with coarse, stiff white hairs, while the remainder is covered with a drab powder that soon sloughs off to leave the stipe polished, and more or less the same color as the cap. It also exudes a bright or dull-red juice when cut or broken.Smith 1947, pp. 146–49. The edibility of the mushroom is unknown—but it is considered too insubstantial to be of culinary interest.

The spores are 8–10 by 4–5 μm, roughly ellipsoid, and only weakly amyloid. The basidia (spore-bearing cells) four-spored (occasionally two- or three-spored). The pleurocystidia ( cystidia on the face of a gill) are rare to scattered or sometimes quite abundant, narrowly to broadly ventricose, measuring 36–54 by 8–13 μm. They are filled with a sordid-reddish substance. The cheilocystidia (cystidia on the gill edge) are similar to the pleurocystidia or shorter and more obese, and very abundant. The flesh if the gill is made of broad hyphae the cells of which are often vesiculose (covered with vesicles) in age, and stain pale reddish brown in iodine. The flesh of the cap is covered with a thin pellicle, and the hypoderm (the layer of cells immediately underneath the pellicle) is moderately well-differentiated. The remainder of the cap flesh is floccose