Inocybe fastigiata

Also known as Inocybe rimosa

CORN SILK INOCYBE

Order: Agaricales, family Inocybaceae

CAP BROWNISH WITH KNOB, FIBROUS

Cap: 2-8 cm wide; conical becoming flat with prominent central knob; cap edge upturning, often split; yellow-brown to brown; fibrous; odor spermatic or mealy or lacking

GILLS WHITISH THEN BROWNISH WITH AGE

Gills: attached, becoming nearly free; narrow, crowded; whitish, then brownish with age

STALK FIBROUS WITH NO RING

Stalk: 4-9 cm long, 4-9 mm wide; fibrous

SPORE PRINT BROWN

Spores: 9.5-14.5 x 6-8.5, elliptical, smooth

Inocybe fastigiata

⚠️ POISONOUS

FOUND ON DUFF UNDER TREES

LOOKALIKES 

Agrocybe sp. -- no fibrous cap

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Inocybe rimosa is indistinguishable from dozens of other species of Inocybe. All in the genus are poisonous, and can be recognized by the distinct central bulb, radial fibrils and splitting edge.

Inocybe is a common genus in the mountains, but rare in the city. It has a "mycorrhizal" (my-coh-rise-ul) relationship with trees, which means the underground portion of the shroom (the mycelium) exchanges nutrients with the roots of the tree, benefiting both organisms. Most mushrooms growing in the mountains have mycorrhizal relationships with trees. But most urban mushrooms are not mycorrhizal.

Overall, the Inocybe genus is not all that exciting, and this urban variety is no exception. David Arora describes this genus this way: "Listless, lackluster...an endless, senseless, procession of drab browns, sordid yellows, dismal grays, and wishy-washy whites." They contain the same poison as Clitocybe dealbata, causing—among other problems—profuse sweating.