Summary:
Features include 1) a hygrophanous, viscid, sharply conic-umbonate, olive or olive-buff cap, 2) blue-violet to violet-gray young gills, 3) a stem that is faint bluish-gray to greenish or drab at the top and orange to brownish in the lower part, narrowing downward into a prolonged pseudorhiza, and 4) microscopic characters. It is a member of Phaeocollybia festiva complex which comprises small to moderately sized, relatively fragile, relatively odorless/tasteless fruitbodies with conic-bellshaped, glutinous caps, rosy to violet gills, spores that are medium to large (7-9(10) x 4-5.3 microns), limoniform to fusiform (naviculate), and roughened (rugulose-ornamented, best described as marbled), cheilocystidia that are thin-walled, +/- clavate, and emanate from the gill trama, and highly gelatinized tissues lacking clamp connections (from Norvell(5) and Norvell(11)). See SIMILAR to differentiate the other Pacific Northwest species in the Phaeocollybia festiva complex which are P. lilacifolia and P. rifflipes, (Norvell(11)). This analysis disagrees with the previous disposition of P. lilacifolia A.H. Sm. as a synonym of P. fallax A.H. Sm. in Horak(1). Note that A.H. Smith''s original description indicated that the top of the stem was "caesius" [pale grayish blue or perhaps lavender] rather than dull drab to greenish as implied by Norvell(5) p. 109. It is relatively common in the Pacific Northwest.

Cap:
(1)2-6.5cm across, broadly bell-shaped with low to prominent conic umbo, flat margin and incurved edge; "usually some shade of pale to dark olive green"; bald, viscid to glutinous, (Castellano), 1-5cm across, conic with inrolled margin when young, expanding to flat with prominent conic umbo; hygrophanous, "deep-olive" to "buffy-olive" when fresh, fading to green ("veviter green" or "water green"); bald, glutinous when wet to viscid when dry, "when partly faded the margin faintly striatulate", (Smith who also refers to cap as dark olive to olive-green), about 1.5-6.5(9)cm across, "at first conic-convex with acute conic umbo, incurved margin and inrolled edge", expanding to broadly bell-shaped with low to prominent conic umbo, flat margin, and incurved edge; hygrophanous, when young some shade of light to dark olive-green, often variably shaded with different greens in patches or zonate with darker disc and paler edge, green at times obscured by dark orange or brown gluten, when old green fading to brownish olive, dried cap "greenish metallic bronze to satiny greenish to blackish brown"; "viscid to glutinous, smooth, bald", "with noticeably striate edge when moist", (Norvell(11)), 1-5cm across, conic expanding to flat with distinct pointed umbo, margin inrolled when young; hygrophanous, olive or olive-buff fading to light yellow-green; smooth, slimy when wet, margin becoming faintly striate when older, (Phillips), the olive-green surface, which usually darkens when old or with exposure, can also be obscured in young specimens by a bright orange-brown to dark brown gluten, (Norvell(5) who notes that P. fallax was "originally also [as well as blue-violet gills] characterized by a sharply conic-umbonate glutinous pileus, dull drab to greenish stipe apex above a hollow polished orange stipe, and a moderately small stature and fragile aspect")

Flesh:
firm, brittle, thick at the disc, thin at the margin; olive-green fading to olive-buff, (Phillips), thick in disc, thin in marginal area; olive-green fading to olive-buff, (Smith), thin at the margin, up to 0.5cm thick at disc; olive buff to deep olive, often consumed by insects, (Norvell(11))

Gills:
narrowly attached; "blue-violet when young but soon becoming dull pink-brown", (Castellano), free or scarcely attached, close, narrow, equal; ''at first "pale violet plumbeous" to "deep plumbago gray" (caesious), slowly becoming rusty-brown from the spores''; the edges serrate to eroded, (Smith, who also refers to gills as violaceous), "Bluish violet when young, dulling to drab, orange cinnamon with ruffled whitish edges in age", (Norvell(11)), "free or slightly adnexed, close, narrow; violet to violet-gray becoming rust-brown", (Phillips)

Stem:
up to 27.5cm long overall with part above ground up to 6-8cm long, 0.3-0.8(1.2)cm wide at top, equal or narrowing downward, usually hollow surrounded by cartilaginous rind; dull olive to somewhat gray at top, "becoming orange to orange-brown from ground upwards"; smooth except for occasional fibrillose patches at top, (Castellano), 8-12cm x 0.4-0.8cm, narrowing downward into a prolonged pseudorhiza, stem cartilaginous, tubular to hollow; faintly caesious or grayish at the top; bald or with sparse, irregularly arranged, appressed patches of brownish fibrils as seen under handlens, (Smith), about 3-10cm above the ground, combined length with pseudorhiza more than 27.5cm, about 0.3-0.8(1.2)cm wide at top, more or less central, aerial portion usually slightly fusiform [spindle-shaped], occasionally equal or tapering, pseudorhiza vertical-monopodial [unbranched, fleshy], about 3/4 of overall length, continuous with stem and gradually tapering to a curled or nippled origin; "young apex grayish drab or dull olive buff, grading to deep orange to orange-brown at ground level", becoming uniformly orange to orange-brown when old, pseudorhiza "deep orange to dark reddish brown"; stem surface "viscid to moist, smooth and +/- polished beneath short fibrillose patches, shiny", (Norvell(11)), 7-12cm x 0.3-1cm, hollow, tapering to a long root-like base; faint bluish gray at top, brownish in lower part from minute, fine hairs; smooth, cartilaginous, (Phillips), although Smith described stem as "tubular-hollow", stems stuffed with relatively firm (i.e. not fibrillose) flesh have been observed, (Norvell(11))

Veil:
veil remnants present "as irregularly arrayed short appressed orange or dark brown fibrillose patches" on aerial part of stem, (Norvell(11))

Odor:
"not distinctive to complex with slight floral undertones (reminiscent of pansies, boiled potatoes, or burnt wet hair)", (Norvell(11)), slightly floral to reminiscent of burnt hair, (Castellano), radish-like when crushed (Smith), radishy (Phillips)

Taste:
usually mild, occasionally radish-like, gluten sometimes bitter when fruitbodies old, (Norvell(11)), somewhat of radish, occasionally bitter, (Castellano), mild (Smith, Phillips), usually mild, but numerous older specimens were found to have caps with bitter-tasting cuticles and / or gluten, (Norvell(5))

Microscopic spores:
spores 7.5-10.5 x 4-6 microns, lemon-shaped - fusoid with moderate apical beak and distinct apiculus, finely to moderately ornamented; cheilocystidia thin-walled, broadly clavate intermixed with slightly capitate elements, colorless and often encrusted with colorless gelatinous secretions, packed into dense gelatinous barrier on gill edge; cap cuticle "a two-layered ixocutis with a hyaline, highly gelatinized top layer and a bright orange to brown-orange bottom layer"; clamp connections absent, (Castellano), |spores 7-9 x 4.5-5.5 microns, ovate with a small apical beak in face view, inequilateral in side view, "verruculose, the inner wall thickened, dark rusty-brown in KOH, an apical pore present in the beak but very small and the beak paler than the remainder of the spore"; basidia 4-spored, 30-33 x 7-9 microns; pleurocystidia none, cheilocystidia 35-42 x 7-9 microns, "clavate, mostly resembling immature basidia", yellowish to colorless in KOH; cap cuticle in the form of a tangled turf of gelatinous, colorless, smooth hyphae 2-3 microns wide, very well developed; clamp connections absent, (Smith), |spores 7-10 x 4-6 microns, average 9 x 5.3 microns, in face view "ovate with elongated apical beak and pointed apiculus", in side view limoniform-fusoid with eccentric apiculus and long central to slightly tilted tapered beak (up to 1.5 microns), verrucose-rugulose (marbled), in KOH medium amber brown, in water paler, in Melzer''s reagent dextrinoid; basidia 4-spored, 30-42 x 7-9 microns, clavate, granular, colorless to yellowish; pleurocystidia absent, cheilocystidia abundant, thin-walled, arising from gill trama "to form a dense gelatinous sterile layer with individual elements frequently surrounded by apical gelatinous secretions in KOH", broadly clavate 7-9 microns wide elements "intermixed with long pedicelled subcapitate elements" that have apices 5-7 microns wide, yellowish or colorless in KOH, "apical extensions from senescent elements rare"; cap cuticle a two-layered ixocutis, the suprapellis about 500 microns thick, a tangled turf of long, branched, narrow (2-4 microns wide), straight to curly, highly gelatinized, colorless hyphae in a thick gelatinous matrix, the subpellis about 400 microns thick, with thicker-walled, inflated (up to 15 microns from 6-10 microns wide septa), gelatinized hyphae with intraparietal pigments that are orange in KOH and greenish in water; tibiiform diverticula "abundant on mycelial and external primordial hyphae, also frequent on remnants of pellicular veil" on stem apex, up to 20 x 1 microns, highly refractive, colorless, "with no septum between base and hyphae, with/without (sub)globose head and/or apical droplet"; clamp connections absent in all tissues, (Norvell(11)), |spores 8-9 x 5-6 microns, oval, warty, with pore-like beak at tip, (Phillips), although some collections were found to have the "basidia-like" cheilocystidia originally described and illustrated by Smith, "a much greater proportion (including some type specimens) were found to be dominated by distinctly subcapitate cheilocystidia" (which Smith considered more characteristic of P. lilacifolia): it ''would appear that a more reliable diagnostic character is the fact that in KOH, "fallax" cheilocystidia characteristically exude a clear heavy gel that eventually spreads out into a dense gelatinous matrix'', ''evidence of this matrix can also be seen in squash mounts in which the abundant cheilocystidia stick together in a dense agglutinated "barrier", particularly in older or poorly preserved specimens'', (Norvell(5))

Spore deposit:
pinkish cinnamon (Norvell(11)), dark rust (Phillips)

Notes:
Phaeocollybia fallax is known from about 100 sites in BC, WA, OR, ID, and CA, and is also reported from Mexico, (Norvell(11)).

EDIBILITY

no (Phillips)