Stropharia hornemannii
Description
Stropharia hornemannii is a species of agaric fungus in the family Strophariaceae. It is found in Europe and North America, where it grows as a saprophyte on rotting conifer wood. It is inedible and may be poisonous.
This large, charismatic Stropharia with a sticky, reddish-brown to purple-brown or brown cap and a thick, scaly stem. Like other species of Stropharia, it features a dark, purplish-brown spore print.
Common names: Luxuriant Ringstalk, Conifer Roundhead, Lacerated Stropharia.
Mushroom Identification
Ecology
Saprobic; growing alone, scattered, or in clusters on duff and woody debris in boreal and montane forests; often found fruiting from well-decayed wood; summer and fall; widely distributed in northern and montane North America.
Cap
3.5–8 cm; convex to broadly conic when young, becoming broadly convex, nearly flat, or broadly bell-shaped; sticky when fresh; bald; sometimes appearing slightly radially streaked; reddish-brown to purple-brown or brown when young, but usually fading quickly to tan or pale yellowish-brown; often adorned with white veil remnants near the margin.
Gills
Broadly attached to the stem or, with age, beginning to pull away from it; close; short-gills frequent; pale gray at first, later purplish gray to purple-black.
Stem
6–10 cm long; 1–1.5 cm thick; equal; dry; with a fairly persistent, skirtlike, white ring featuring a grooved upper surface that becomes dusted with purple-black spore dust; below the ring conspicuously shaggy-scaly with whitish girdles, especially when young; base attached to white mycelial threads.
Flesh
White; unchanging when sliced, or turning slightly yellowish.
Odor and Taste
Odor somewhat foul, or reminiscent of pumpkin. Taste not distinctive.
Spore Print
Dark purple-brown to blackish.
Similar Species
Panaeolus semiovatus also has a silky smooth cap, but it is much paler and grows on dung; its gills blacken to provide a black spore print.
Microscopic Features
Spores 12–15 x 6–7.5 µm; ellipsoid; with a small pore; smooth; brown in KOH. Cheilocystidia as leptocystidia; 40–60 x 15–20 µm; widely lageniform to subutriform; thin-walled; hyaline in KOH. Pleurocystidia as chrysocystidia; 50–70 x 10–15 µm; lageniform to utriform; thin-walled; smooth; with or without refractive, yellowish to golden inclusions. Pileipellis an ixocutis; elements 4–5 µm wide, smooth, yellowish in KOH, clamped at septa.
History
Although Christiaan Hendrik Persoon has described this mushroom as early an 1801 and called it Agaricus depilatus, its basionym dates from 1818, when the great Swedish mycologist Elias Magnus Fries described the Conifer Roundhead scientifically and gave it the binomial name Agaricus hornemannii. In 1934 Swedish mycologists Seth Lundell (1892 - 1966) and John Axel Nannfeldt (1904 - 1985) transferred this species to the genus Stropharia, establishing its currently accepted scientific name Stropharia hornemannii.
Synonyms of Stropharia hornemannii include Agaricus depilatus Pers., Agaricus hornemannii Fr., and Stropharia depilata (Pers.) Fr.
Stropharia, the genus name, 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 hornemanii is in honor of the Danish botanist Jens Wilken Hornemann (1770–1841).
Photo sources:
Photo 1 - Author: Chris Kleine (ckleine) (CC BY-SA 3.0)
Photo 2 - Author: Chris Kleine (ckleine) (CC BY-SA 3.0)
Photo 3 - Author: Chris Kleine (ckleine) (CC BY-SA 3.0)
