Russula fragilis

Description

Russula fragilis is a small to small-medium species with very fragile flesh that becomes water-soaked very quickly. The cap color is generally a mix of watery purple, pink, and olivaceous green on a whitish to grayish background, and the cap edge is translucent-striate. The spores are white, the odor mild or pleasantly fruity, and the taste very acrid. It occurs singly or in small groups, often on or near well-rotted wood.

This mushroom is inedible due to the toxins it contains and it is a very hot taste. Many hot-tasting Russula species cause problems of a gastrointestinal nature when consumed, resulting in diarrhea, and vomiting.

Common names: Fragile Brittlegill, Fragile Russula.

Mushroom Identification

1. Cap

   2 to 6cm diameter, often noticeably grooved at the margin, the caps are initially convex, then expanding and becoming depressed. Very brittle. Most are violaceous or purple, darker in the center, and sometimes taking on a green tinge when old. The cap flesh white.

2. Gills

   The very brittle gills are adnate, white or pale cream, with toothed edges. (This latter feature is only visible with a magnifying glass.)

3. Stem

   2 to 6 cm long and 5 to 10mm in diameter, the stems are white, sometimes tinged yellow near the base. The slightly swollen base is particularly brittle. The white flesh of the stem crumbles very easily.

4. Spores

   Globose (almost spherical), 7.5-9 x 6-8µm; ornamented with warts up to 0.5µm tall connected by fine lines to form an almost complete network.

5. Spore print

   White.

6. Odor and Taste

   Slight fruity odor; acrid taste.

7. Habitat & Ecological role

   In broadleaf woodland and sometimes also in coniferous woodland, preferring damp, well-shaded places; usually scattered rather than in large groups. In common with other members of the Russulaceae, Russula fragilis is an ectomycorrhizal mushroom.

8. Similar Species

   Russula atropurpurea, the Purple Brittlegill, is much larger with a very dark, almost black cap center and pale cream gills; its stem base is rusty brown.

History

Russula fragilis was described in 1801 by Christian Hendrik Persoon, who gave it the binomial scientific name Agaricus fragilis. In 1838 the Fragile Brittlegill was transferred to the Russula genus by the great Swedish mycologist Elias Magnus Fries, whereupon its scientific name became Russula fragilis.

Synonyms of Russula fragilis include Agaricus fallax Schaeff., Agaricus fragilis Pers., Agaricus linnaei var. fragilis (Pers.) Fr., Russula bataillei Bidaud & Reumaux, Russula emetica var. fragilis (Pers.) Quél., and Russula fragilis var. fallax (Schaeff.) Massee.

Russula, the generic name, means red or reddish, and indeed many of the brittlegills have red caps. The specific epithet fragilis means fragile, of course, and indeed this just has to be one of the most brittle of brittlegills!

Photo sources:

Photo 1 - Author: Jerzy Opioła (CC BY-SA 3.0)

Photo 2 - Author: MichalPL (CC BY-SA 4.0)

Photo 3 - Author: {{{2}}} (CC BY-SA 3.0)