Stropharia caerulea - Blue Roundhead

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

Stropharia caerulea is one of very few blue-green fungi. (In most instances the caps are much nearerer to green than to blue, but when young and fresh they are very beautiful and quite startling. The caps, initially bell-shaped, flatten and turn paler from the centre. White scales near the cap rim help to identify this unusual fungus.

The fine specimens pictured on the left were photographed by Janet Hill, with whose kind permission they are shown here.

Identification Guide

	Cap Young caps are bell-shaped, blue-green and slimy, peppered with small white veil fragments. Older specimens, like the one illustrated here, are paler and scaly mainly near the rim of the cap, which expands but does not completely flatten out. The slime dries up on older caps, which gradually turn pale tan from the centre outwards. The cap diameter at maturity ranges between 2 and 8cm.
	Gills At first pale grey, the crowded sinuate gills become purple-brown as the spores mature.
Stem	White above the ring, which is transient and soon discoloured by falling spores; pale blue-green below and peppered with small white scales. 5 to 12 mm in diameter and 2 to 6cm tall.
Spore print	Purple-black.
Odour/taste	Not distinctive. Inedible and probably poisonous.
Habitat	In small groups among grass and occasionally leaf litter in woodland and in pastures.
Season	July to October.
Occurrence	Fairly frequent, especially in chalky areas.
Similar species	Stropharia aeruginosa is darker blue-green and its cap scales are persistent; it has reddish-brown gills with white edges; it is much less common than Stropharia caerulea. Clitocybe odora is also blue-green but does not have a slimy cap with scales; it has a strong odour of aniseed.