65 8 THE AGARICACEAE OF MICHIGAN 



Key to the Species 



(A) Stem eccentric; pileus entire or at least marginate behind; plants 

 of medium size to very large, 

 (a) Pileus brown or blackish brown, umbonate, 2-7 cm.; gills subdis- 



tant, broad; spores 5-6 x 4-5 micr. P. umbonatus Pk. 

 (aa) Pileus yellow, yellowish or reddish. [See also (aaa).] 



(b) Pileus glabrous, gelatinous on top, coarsely-reticulate, pinkish or 

 flesh color; spores globose, echinulate. 699. P. subpalmatus 

 Fr. 

 (bb) Pileus strigose hairy, scaly or fibrillose. 

 (c) Very large; pileus lateral, cream-color then yellowish, strigose 

 hairy; gills very broad; stem short. (See 12a. Panus strigo- 

 sus B. & C.) 

 (cc) Medium-size; stem medium long and not very eccentric. 



(d) Pileus and stem densely dotted with brown or blackish 

 scales; spores globose, minute. (See 760. Clitocybe decora 

 Fr.) 

 (dd) Pileus unicolorous, silky-flbrillose, umbonate; spores ellipti- 

 cal, 7-9 x 5-6 micr. 698. P. sulfuroides Pk. 

 (aaa) Pileus white when young or fresh, 

 (b) Plant large, on standing elms, etc., stem rather long and stout; 

 gills emarginate or sinuate, rounded behind, broa'd. 696. P. 

 ulmarius Fr. 697. P. elongatipes Pk. 

 (bb) Gills adnate, adnate-decurrent or long-decurrent. 



(c) Spore print pale dingy lilac; pileus thinner and more flaccid 



than P. ostreatus. 702. P. sapidus Fr. 

 (cc) Spore print white. 



(d) Stem stout, usually quite short, 

 (e) Gills running down the stem in lines and anastomosing; 



plant rather stout. 700. P. ostreatus Fr. 

 (ee) Gills not anastomosing on stem, but strongly decurrent. 

 Spores longer than in the preceding two, 12-15 x 5 micr. 

 701. P. subareolatus Pk. 

 (dd) Stem slender, 2-5 mm. thick; gills narrow and crowded, 

 (e) Pileus hygrophanous, hyaline-white, thin; stem solid, pru- 

 inose-floccose. 705. P. fimbriatus var. regularis var. nov. 

 (ee) Pileus not hygrophanous, tough, medium size to small, 

 (f) Dingy-white; pileus irregular; stem curved, subvillose, 



odor farinaceous-oily. 703. P. lignatilis Fr. 

 (ff) Entirely white; pileus regular, orbicular; stem straight, 

 glabrous; odor faint. 704. P. circinatus Fr. 

 (AA) Stem none or very short; pileus sessile or continuous with the 

 stem, 

 (a) Pileus at first resupinate. 



(b) Upper layer of pileus gelatinous, forming a pellicle, 

 (c) Pileus 2-5 cm. broad, more or less reniform to obovate. 



(d) Pileus gray or blackish-brown, margin paler, villose, gills not 

 very broad, whitish. 714. P. atrocaeruleus Fr. var. griseus 

 Pk. 

 (dd) Pileus rich brown, covered with squarrose or erect scales; 

 gills broad, grayish-white. 713. P. mastrucatus Fr. 

 (cc) Pileus minute, in the shape of a pendulous, reversed vase or 

 cup, pale gray; on herbaceous stems. P. cyphellaeformis Berk, 

 (bb) Pileus without a gelatinous pellicle, 

 (c) Pileus pure white, rarely varying to pale tan. 

 (d) Pileus 3-7 cm. long, flabelliform, obovate or cuneate; gills 

 narrow, crowded, forked, 

 (e) Pileus tomentose; spores spherical; gills scarcely forked. 



713. P. albolanatus Pk. 

 (ee) Pileus glabrous, margin involute; spores longer than 

 broad; gills forked. 710. P. porrigens Fr. 



