Summary:
Features include large size, white color when young, close to crowded gills, tough flesh, resistance to decay, and a mycelial mat surrounding the base. Singer(19) and Singer(5) give several varieties and forms of which at least the five following occur in the Pacific Northwest. All five were regarded as separate species in the online Species Fungorum, accessed October 20, 2017. 1) var. typicus (=L. albissimus) is bitter and pure white either fresh or (properly) dried, 2) var. piceinus (= L. piceinus) is bitter and when old is buff to tan at least in places, (white to cream, often developing a tan disc, when old pale sordid ochraceous, also sometimes having anastomosing ridges at the top of the stem not found in var. typicus), 3) var. lentus (= L. lentus) is mild in taste and bald over the midportion of the stem, the stem not exceeding 1.5cm wide (forma typicus with stature of a Tricholoma, forma olympianus with stature of a Clitocybe and few gills forked, and forma furcatus with stature of a Clitocybe and many gills forked), 4) var. paradoxus (= L. paradoxus) is mild and is not bald over mid-portion of stem, stem may exceed 1.5cm wide, (forma albiformis of this variety differing from forma euparadoxus in yellower dried gills and more consistently fusoid stem), according to Arora(1) similar in color to var. piceinus, 5) var. montanus (= L. montanus) is like var. paradoxus but with abundant cheilocystidia or like var. piceinus with mild taste. One of the descriptions here is derived from Arora(1) who says he is basing it primarily on var. paradoxus (= L. paradoxus), although he gives taste as mild or bitter and Singer(19) give mild taste for this variety. The Singer(19) description below is for var. typicus.

Cap:
5-20(40)cm across, convex with inrolled margin when young, becoming flat or depressed when old; "white becoming buff, yellowish or even tan (at least toward center) in age"; "dry, dull, unpolished", often cracked or splitting when old or dry weather, margin sometimes obscurely ribbed, (Arora), (3)5-6(7)cm across, convex becoming more or less expanded, margin involute; "pure white, remaining white when dried or very rarely subalutaceous over the disc"; bald, smooth or rarely faintly rimose-areolate [cracked like dried mud] when old, scarcely shining, margin "slightly subtomentose when young, usually ribbed but sometimes smooth", (Singer(19))

Flesh:
thick, tough; white, (Arora), soft, not watery; pure white, unchangeable, (Singer(19))

Gills:
"attached (typically decurrent at least by lines, but ranging to adnate or even adnexed)", close; white, to slightly yellowish when old, (Arora), "adnate with a decurrent tooth or simply decurrent", some with short rib-like proliferations down top of stem, ribs not anastomosing, crowded or subcrowded, occasional gills forking at base, mostly non-anastomosing, moderately broad (up to 0.6cm), subgills abruptly rounded at inner extremity; white and unchanging even in dried material (if properly dried), (Singer(19))

Stem:
5-20cm x 1-5cm, equal or widened at the middle or below (often with a narrowed base), tough, solid; white, discoloring slightly when old; smooth or often scaly (especially in middle part), base usually embedded in a white mycelial mat, (Arora), 4-7cm x 0.7-1.5cm, subequal but base often bulbous with adherent remnants of leaves or needles, stem solid; white; "subglabrous or somewhat fibrous-scabrous (especially at the apex)", (Singer(19))

Veil:
none (Arora)

Odor:
unpleasant or fragrant (Arora), "aromatic and sweet but often weak" (Singer(19))

Taste:
mild or bitter (Arora), farinaceous-bitter (Singer(19))

Microscopic spores:
spores 5.5-8.5 x 4-6 microns, elliptic, warty, amyloid, (Arora), spores 5.5-7.5(8.5) x 4.2-5.5 microns, elliptic to oval, strongly amyloid; basidia 4-spored, 24-36 x 6.5-8.5 microns; pleurocystidia none, cheilocystidia extremely rare or lacking; clamp connections abundant, (Singer(19)), spores 6.5-8 x 4.5-5.5 microns, broadly elliptic, strongly amyloid, with small scattered warts (at times appearing almost smooth); basidia 4-spored, 36-42 x 8-9.5 microns, clavate; pleurocystidia rare and found mostly near gill edge, 34-46 x 3-5 microns, flexuous [wavy], colorless, cheilocystidia very abundant to scattered, similar to pleurocystidia; clamp connections mentioned for cap trama, (Singer(5) for var. monticola)

Spore deposit:
white (Arora)

Notes:
Singer(5) give var. typicus for at least OR (Singer(19) studied this variety from ON, MI, NH, and NY). Singer(19) examined collections of var. piceinus from OR, NS, ON, MI, IL, and TN, and Hardy (as referred to in Redhead(5)) reported var. piceinus from BC. Singer(19) examined collections for var. lentus from WA (forma typicus, forma olympianus, and forma furcatus). Singer(19) examined collections of var. paradoxus forma albiformis from WA, OR, CA and of var. paradoxus forma euparadoxus from CA. Singer(5) described var. montanus from ID and reported it from CA and NH. There are collections of Leucopaxillus albissimus from BC at the Pacific Forestry Centre and the University of British Columbia.

EDIBILITY

coarse and difficult to digest (Arora)