Laccaria amethysteo-occidentalis
western amethyst laccaria ('western amethyst Laccaria')
Hydnangiaceae

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

Photograph

© Jim Riley     (Photo ID #52707)


Map

E-Flora BC Static Map

Distribution of Laccaria amethysteo-occidentalis
Click here to view the full interactive map and legend

Species Information

Summary:
Features include 1) a hygrophanous, violet to brownish purple cap, 2) sinuate well-spaced gills that are purple to lavender; 3) a long, dry, striate, purple violet stem with violet mycelium at base, 4) mild odor and taste, 5) growth under conifers, 6) a white spore deposit, and 7) finely spiny spores that are nearly round to broadly elliptic. Laccaria amethysteo-occidentalis is common in the Pacific Northwest.
Cap:
1-6.5(8.9)cm across, obtuse to convex to flat, often depressed, margin inrolled to decurved [downcurved] at first; hygrophanous, deep purple when fresh, fading to vinaceous, finally becoming buff; not striate when fresh, but sometimes translucent-striate on fading, finely fibrillose to fibrillose-scaly, (Mueller(1))
Flesh:
thin, concolorous with lighter gray purple to white areas intermixed; in stem colored as in cap, (Mueller(1)), violet (Phillips)
Gills:
sinuate to arcuate, subdistant to distant, narrow to broad, thick, occasionally waxy; dark violaceous, fading lighter (near "lavender" Ridgway(1) color), (Mueller(1)), royal purple to lilac when young, "and retaining purple tones longer than cap, before fading to pinkish buff", (Siegel)
Stem:
1.8-11.5cm x 0.3-1.2cm, equal to subclavate [somewhat club-shaped], occasionally slightly bulbous; purple, often with lighter violet to white scattered sectors, basal mycelium violet; dry, longitudinally striate, occasionally with recurved [upcurved] scales, (Mueller(1)), purple, purplish gray, purple-brown, pinkish buff to grayish beige, "typically with numerous whitish or pale buff loose fibrils and scurfs", (Siegel)
Odor:
not distinctive (Phillips)
Taste:
not distinctive (Phillips)
Microscopic spores:
spores (6.4)7.4-10.6 x 6.4-9.2 microns excluding ornamentation, nearly round to broadly elliptic, occasionally round or elliptic to almond-shaped, echinulate [spiny], echinulae < 0.5-1.4(1.8) microns long, (mean 1 +/- 0.3 microns), crowded, inamyloid, acyanophilic, hilar appendix 1.3-2 microns long, prominent, and truncate, plage present, occasionally one droplet; basidia 4-spored, 34-56.5 x 9.7-14.7 microns, clavate, elongate, colorless or in young specimens vinaceous brown in mass, sterigmata up to 9 microns long; pleurocystidia absent, cheilocystidia often abundant, extending well beyond basidia, 36.5-66.5 x 12-18.4 microns, subclavate to clavate, colorless, thin-walled, colorless, (Mueller(1)), spines on spores 1 micron wide at base, (Mueller(2))
Spore deposit:
white (Mueller(2))
Notes:
Mueller(1) examined collections from BC, WA, OR, and CA. Oregon State University has a collection from ID.
EDIBILITY
yes (Phillips)

Habitat and Range

SIMILAR SPECIES
Laccaria amethystina is similar (and in the same group) but has nearly round, moderate to long-spined spores, (instead of nearly round to broadly elliptic short-spined spores), and is smaller and less deep purple, (Mueller(1)). L. amethystea fades to buff or gray rather than vinaceous or buff or brown. The other North American purple Laccaria, Laccaria vinaceobrunnea, is similar but L. amethysteo-occidentalis has robust size, a different color of the mature fruiting bodies, and microscopically a cap cuticle of scattered fascicles rather than individual perpendicular hyphae, (Mueller(1)). Neither L. amethystina nor L. vinaceobrunnea is known to occur in the Pacific Northwest. See also SIMILAR section of Laccaria bicolor.
Habitat
scattered to gregarious under conifers, often Pseudotsuga menziesii (Douglas-fir), (Mueller(1)), fall, winter