Macrocystidia cucumis - Cucumber Cap

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

This caps of this attractive red-brown fungus are difficult to spot among the dead beech leaves that litter their most usual habitat. You are quite likely to find these mushrooms in disturbed sites beside country lanes, and they are increasingly common now that woodmulch is used so much in gardens and parks.

The specific epithet comes from the odour of cucumber (although one of our colleagues says that to him they smell rather more like salmon sandwiches).

Identification guide

Cap	The cap is pruinose or velvety and conical at first, becoming more shiny and bell-shaped with age but not expanding to become completely flat; diameter 1 to 6 cm; red-brown or date brown with the rim area a paler yellow-brown.
	Gills Cream at first, becoming pale pinkish-beige with age, the gills are broad, crowded and free. Stem 3 to 8mm diameter; cream or beige at the apex, graduating to dark brown at the base; velvety surface.
Spores	Pale pinkish-brown.
Odour/taste	Odour of cucumber; taste not distinctive.
Habitat	Usually in small groups on disturbed, rich soil; most common under broad-leaf trees, particularly beech, but also in hazel coppices and occasionally under conifers
Season	Fruiting from July through to December; most abundant in October and November.
Occurrence	Widespread and fairly common.
Similar species	Pluteus cervinus is more viscid and grows on rotting wood rather than in soil; its cap usually flattens, whereas caps of Macrocystidia cuccumis remain more bell shaped.