Macrolepiota mastoidea - Slender Parasol

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

Macrolepiota mastoidea, the Slender Parasol, favours calcareous woodlands and grasslands. These latge mushrooms also occur in coastal dunes in what would otherwise be acidic areas where it not for the presence of broken sea shells that raise the alkalinity of the thin soil; in some dune systems Slender Parasols appear in large numbers. If you gather these mushrooms to eat, be aware that the somewhat similar Shaggy Parasol, Chlorophyllum rhacodes, can cause tummy upsets.

Identification guide

	Cap Initially spherical and pale brown with a darker brown area near the crown that breaks into scales, the cap expands until it is flat with a small umbo. The flesh of this mushroom gradually turns brown but does not redden noticeably when cut or bruised. The cap diameter at maturity ranges between 5 and 15cm.
	Gills The broad, crowded gills, some of which fork, are white or pale cream and free, terminating a small distance from the stipe. Stem A double ring, the upper face pale and the lower face brown, usually persists around the stem but often becomes movable and occasionally falls to the base. The surface is white and covered with small, closely spaced yellowish-brown scales. Slightly bulbous at the base, the stem tapers inwards towards the apex; its diameter ranges from 0.6 to 1.5cm, and the height varies between 6 and 16cm.
Spore print	White or pale cream.
Odour/taste	Odour slight, 'mushroomy'; taste mild but not distinctive.
Habitat	In woodland clearings and in grassy areas next to woodland.
Season	July to November.
Occurrence	Frequent.
Similar species	Macrolepiota procera, the Parasol, is larger and has a snakeskin-like pattern on its stem. Chlorophyllum rhacodes, the Shaggy Parasol, has reflexed scales and a smooth stipe; its flesh reddens when cut or bruised.