Laccaria amethysteo-occidentalis G.M. Muell.
western amethyst Laccaria ('western amethyst Laccaria')

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

Introduction to the Macrofungi


© Jim Riley     (Photo ID #52707)


E-Flora BC Static Map

Distribution of Laccaria amethysteo-occidentalis
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Species Information

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))
thin, concolorous with lighter gray purple to white areas intermixed; in stem colored as in cap, (Mueller(1)), violet (Phillips)
sinuate to arcuate, subdistant to distant, narrow to broad, thick, occasionally waxy; dark violaceous, fading lighter (near "lavender" Ridgway(1) color), (Mueller(1))
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))
not distinctive (Phillips)
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))
yes (Phillips)

Habitat and Range

Laccaria amethystina is similar (and in 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)). It 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, different color of 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.
scattered to gregarious under conifers, often Pseudotsuga menziesii (Douglas-fir), (Mueller(1)), fall, winter