Russula fragilis var. fragilis (Pers.) Fr. - Fragile Brittlegill

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Russulales

Russula fragilis, the Fragile Brittlegill, is a small and extremely crumbly species withy a relatively long stem. Although most of these mushrooms have purplish caps, the variety Russula fragilis var. nivea is all white.

Finding an undamaged specimen is far from easy, even though this is quite a commonly occurring little woodland mushroom. The Fragile Brittlegill is bitter tasting and generally considered to be inedible.

Identification Guide

This is a very variable fungus. Cap colour can be pink, violet, purple or white. The coloured specimens have cap centres noticeably darker than the edges. The grooved cap margin is another useful identifying feature.

	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 centre and sometimes taking on a green tinge when old. The cap flesh white. A pure white variety, var. nivea is also fairly common.
	Gills The very brittle gills are adnate, white or pale cream, with toothed edges. (This latter feature is only visible with a magnifying glass.)
	Stem 2 to 6cm 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.
	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. Spore print White.
Odour/taste	Slight fruity odour; acrid taste.
Habitat	In broadleaf woodland and sometimes also in coniferous woodland, preferring damp, well shaded places. In common with other members of the Russulaceae, Russula fragilis is an ectomycorrhizal mushroom.
Season	August to October.
Occurrence	Frequent; usually scattered rather than in large groups.
Similar species	Russula atropurpurea, the Purple Brittlegill, is much larger with a very dark, almost black cap centre and pale cream gills; its stem base is rusty brown.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2011.

The Genus Russula in Great Britain, Geoffrey Kibby 2011.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.