Cortinarius caerulescens - Mealy Bigfoot Webcap

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

Cortinarius caerulescens is found in late summer and autumn growing in deciduous woodland, mainly under beech and oak trees. This very attractive, large fungus is inedible.

When the caps are young, the striking bluish-mauve caps are very distinctive, but like most colourful members of its genus, the Mealy Bigfoot Webcap turns brown from the centre as it matures. The intriguingly lobed specimen shown here is typical of mature caps that have expanded during a dry spell.

Identification guide

	Cap Young caps are convex, later flattening as they expand but invariably retaining an in-rolled margin even when fully developed. The cap diameter varies from 6 to 20cm at maturity. At first a beautiful blue-mauve and particularly fibrilose at the margin, the cap turns ochre-brown, or sometimes rufous-brown, from the centre and becomes more smooth and shiny with age. In dry weather the margin wrinkles, whereas in wetter conditions it tends to remain more regularly circular.
	Gills The notched gills are close and initially white or pale grey. As the spores mature, the gills turn rusty brown, but they usually retain a pale edge until the fruitbody begins decaying.
	Stem The stipe is white at first and clavate (club-shaped), broadest at the base, becoming more parallel-sided as the cap expands. It is covered with long flaky scales below a fleeting ring formed as the cortina parts. Once the cap is fully developed, the stem discolours in patches as rust-coloured spores fall from the gills.
Spore print	Rusty brown.
Odour/taste	Slightly earthy.
Habitat	In deciduous woodland in chalk and limestone areas.
Season	September and October.
Occurrence	Infrequent in warm locations; rare elsewhere.
Similar species	Cortinarius violaceus, the Violet Webcap, has a darker violet cap, gills and stem.