What You Should Know
Stropharia coronilla (Psilocybe coronilla) is a species of mushroom native to Europe and North America. It is considered poisonous. It is a small, cream to a pale yellowish-buff mushroom that is distinguished by a lubricous when moist cap, and annulus with prominent striations on the upper surface, the latter often tinged purple with spores. In lowland pastures and on lawns, this occasional roundhead appears sometimes in small groups but more often singly and widely scattered.
Other names: Garland Roundhead, Garland Stropharia.
Stropharia coronilla Mushroom Identification
Saprobic; growing alone or gregariously on lawns, in pastures, and in other grassy places; summer and fall; widely distributed in North America.
1.5–5 cm; convex, becoming broadly convex or nearly flat; sticky when fresh; bald; golden yellow to brownish-yellow when young and fresh, but sometimes fading to buff.
Attached to the stem; close or nearly distant; short-gills present; pale at first, becoming purplish gray to purple-black.
2–6 cm long; 0.5–1 cm thick; equal, with a slightly tapered base; dry; bald or fibrillose; with a flimsy to persistent ring that is usually grooved on its upper surface and typically collects purplish-gray spores; base sometimes with white mycelial threads.
Soft; white throughout; unchanging when sliced.
Odor and Taste
Dark purple-brown to blackish.
KOH on cap surface slowly pale red.
Spores 7–10 x 3.5–5 µm; ellipsoid; with a small pore; smooth; thick-walled; yellowish-brown in KOH. Chrysocheilocystidia and chrysopleurocystidia 30–50 x 10–12.5 µm; clavate to fusiform; sometimes becoming rostrate; smooth; thin-walled; hyaline in KOH; with refractive globular inclusions. Cheiloleptocystidia to about 40 x 8 µm; clavate or subcylindric; thin-walled; hyaline in KOH. Pileipellis a cutis of elements 2.5–5 µm wide; hyaline in KOH; sometimes somewhat gelatinized.
Stropharia coronilla Look-Alikes
Sometimes expands to almost flat; however, it grows on dung and its gills blacken to provide a black spore print.
Very similar species that features a whiter cap, a longer, slimmer stem, and larger spores.
Stropharia coronilla Taxonomy and Etymology
When French botanist Jean Baptiste Francois (Pierre) Bulliard described this mushroom scientifically in 1793, he gave it the binomial name Agaricus coronillus. It was another Frenchman, Lucien Quélet, who in 1872 transferred this species into the genus Stropharia, thus establishing the currently accepted scientific name as Stropharia coronilla.
Synonyms of Stropharia coronilla include Agaricus coronillus Bull., Agaricus obturatus Fr., and Stropharia obturata (Fr.) Quél.
The genus name Stropharia comes from the Greek word strophos meaning a belt, and it is a reference to the stem rings of fungi in this generic grouping.
The specific epithet coronilla means 'with a crown' and refers to the crown-like patterning on the upper surface of the stem ring.
Photo 1 - Author: Alexey Sergeev (asergeev) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 2 - Author: Daphne Lantier (Creative Commons Attribution 3.0 Unported)