pdvmushroom's Identifications

CFS-31Jan2009-1 Leptonia sp.

Subgenus Cyanula, Section Caesicaules, Series Caesicaules; near the

subviduense complex.

Collected 31 Jan 2009, Mendocino County, California, USA

Cap: 31.6 mm wide, 13.8 mm high. Appressed-fibrillose, broadly convex, margin slightly inrolled and wavy. Deep midnight blue-black. Small umbo (papillate). Flesh 1.6 mm thick at disc. Dingy-white flesh.

Lamellae: 12-16 mm long, 4.2-7 mm deep. Pallid creamy-tan or flesh-colored, quite blue-gray near the stipe, somewhat marginate along the inner 1/2 of some of the larger lamellae. Approximately equal depths. Mostly straight to slightly wavy.

Stipe: 58.7 mm tall. 3.7 mm thick at apex, 3.6 mm thick at lowest point. Medium blue-gray, quite a bit lighter than cap. Glabrous except for distinct scurfs at apex. Striate at base, with distinct mycelial bulb at base – 7.6 mm thick.

Odor: (After 2 days of storage in a tacklebox) – faintly fragrant-pungent or indistinct.

Spores: (10-13.5) 12.1 μm x 6.9 (5.7-7.7) μm, 5-6 sided, heterodiametric.

Pileipellis: Trichodermium, entangled elements (collapsed ?) periclinal at disc, erect away from disc (this seems the opposite of the usual to me).

Stipitipellis: With tufts of cylindrical-clavate caulocystidia.

Cheilocystidia: Collapsed, not abundant, cylindrical-clavate to subcapitate.

Pleurocystidia: Scattered, cyclindrico-clavate, approximately 25 μm tall.

Clamp connections: Absent in all tissues examined (pilepellis, lamellae, stipe, mycelium at base of stipe)

These species can be eliminated by AT LEAST the indicated characteristic (and usually many others):

parva: different pilepellis and pileus color

yatesii: decurrent lamellae

viridiflavipes: color of stipe base, clustered habit

chalybea: basal mycelium scarce to absent, stipe “perfectly” glabrous, pilepellis a palisade

decolorans f. atropruinosipes: stipe covered in dark squamules

decolorans f. decolorans: glabrous stipe

decolorans f. cystidiosa: lacks pleurocystidia, different pilepellis

The L. subviduense group is close but the varieties differ at least in these characteristics:

var. subviduense: Lamellae most often with a decurrent tooth, rarely pruinose at apex, stipe quite fragile, smaller spores.

var. marginata: Cheilocystidia abundant – originate as elements of pileal margin when young and thus identical to pileocystidia, gills serrulate, strongly marginate, stipe “extremely fragile”.

Specimen at UCSC Gilbert Lab.