Agaricacese 



RI'GID^E. 



Russuia. R. lac'tea Fr. lac, milk. Pileus 2 in. broad, at the first milk-white, 

 then tan-white, throughout compactly fleshy , bell-shaped, then convex, 

 often excentric, without a pellicle, always dry, at the first even, then 

 slightly cracked when dry, margin straight, thin, obtuse, even. Flesh 

 compact, white. Stem 1/^-2 in. long, \% in. thick, solid, very com- 

 pact, but at length spongy-soft within, equal, even, always white. Gills 

 free, very broad, thick, distant, rigid, forked, white. Fries. 



Spores subglobose, echinulate, 7~9/x Massee. 



Closely allied to R. albella Pk. from which it differs in its shorter 

 stem, and pileus cracking into areolae, and gills not being entire. 



In mixed woods, in patches, not common. 



Botanic creek, West Philadelphia, Pa., patches, Mcllvaine, 1887. 



Edible and of good flavor. Macadam. 



Raw, it has a raw, rather unpleasant taste and odor, a little like 

 some acorns. But its firm, thick flesh, meaty gills and stem, and good 

 flavor when well cooked, rank it equal to any. 



R. albella Pk. whitish. Pileus 2-3 in. broad, thin, fragile, dry, 

 plane or slightly depressed in the center, even or obscurely striate on 

 the margin, commonly white, sometimes tinged with pink or rosy-red, 

 especially on the margin. Flesh white, taste mild. Lamellae entire, 

 white, becoming dusted by the spores. Stem 1-2 in. long, 3-4 lines 

 thick, equal, solid or spongy within, white. 



Spores white, globose, /.6/* broad. 



Dry soil of frondose woods. Port Jefferson. July. 



Closely allied to R. lactea, but differing in its fragile texture, entire 

 lamellae, more slender stem, and in the pileus not cracking into areas. 

 Peck, 50th Rep. N. Y. State Bot. 



R. vires'cens Fr. viresco, to be green. (Plate XLIV, fig. 6, p. 

 184.) Pileus green, compactly fleshy, globose then expanded, at 

 length depressed, often unequal, always dry, not furnished with a pellicle, 

 wherefore the flocculose cuticle is broken up into patches or warts, margin 

 straight, obtuse, even. Flesh white, not very compact. Stem solid, 

 internally spongy, firm, somewhat rivulose, white. Grills free, some- 



194 



