Parv 4, 1915] AGARICACEAE 201 
11. RUSSULA* Pers. Obs. Myc. 100. 1796. 
Russulina Schrét. Krypt.-Fl. Schies. 31: 550. 1889. 
Pileus fleshy, continuous with the stipe; surface very variable in color, varying in speci- 
mens of the same collection according to light exposure or age, with or without a separable 
cuticle, dry or viscid, glafrous, areolate, squamulose, velvety, or pruinose; margin even, 
striate, or sulcate and tuberculate: context brittle, vesiculose, not lactiferous, mild or acrid 
in taste, sometimes with a distinctly pleasant or disagreeable odor, sometimes changing color - 
where broken or handled; lamellae brittle, rather thin, with acute edges, equal or unequal in 
length, simple or forking, often becoming darker with age or staining where bruised, some- 
times pruinose from the abundant spores; stipe central or nearly so, never fibrous, firm, 
spongy or stuffed, becoming hollow: spores white or yellow, globose to elliptic, usually echinu- 
late. The plants grow on the ground in the woods or in grassy places in open groves or in 
the edges of woods, or occasionally on decaying wood. 
Type species, Agaricus emeticus Schaef. 
Lamellae alternating long and short. 
Pileus without a pellicle. I. ComMpacTak. 
Pileus with a pellicle more or less separable. XX. HETEROPHYLLAE. 
Lamellae dichotomously forking, narrowed at each end. VIII. Brrrpas. 
Lamellae equal or with a few scattered short ones, simple or some of 
them forking once. 
Pileus with the pellicle glabrous at first, breaking up into areolae, 
squamules, or mealy particles, or velvety from the first. 
Pellicle not separable; surface dry, becoming areolate or areolate- 
squamiulose. II. Lepipak. 
Pellicle separable part way to the disk. 
Spores white. 
Odor not characteristic. 
Pileus green or brownish-ochraceous. III, CrustosakE. 
Pileus white or some shade of yellow or pink; margin 
even. VI. INSIGNEs. 
Odor usually foetid. 
Pileus buff to burnt-umber; margin striate. VII. PECTINATAE. 
Spores yellow. 
Lamellae remaining yellow. IV. SUBVELUTINAE. 
Lamellae changing to brownish where bruised, or smoky 
to umber in drying. V. ATROPURPUREAE. 
Pileus glabrous. 
Spores white. 
Taste mild. 
Wounds becoming gray or blackish. XIX. DECOLORANTES. 
Wounds not becoming gray or blackish. 
Pileus yellow. XVII. Frncisiies. 
Pileus red. XXIV. PURPURINAE. 
Taste acrid. : 
Lamellae all equal and simple. 
Pileus yellow, or white tinged with yellow. XII, OcHROLEUCAE. 
Pileus red, red and yellow, vinaceous, violet, or white. XXV. FRAGILEs. 
Lamellae partly short and some forking, chiefly near the 
stipe. 
Pellicle separable, viscid. 
Pileus ochroleucous to snuff-brown or umber; 
margin usually pectinate. VII. PECTINATAE. 
Pileus vinaceous. XI. VINACEAE. 
Pellicle scarcely separable or viscid; piletus red. XIV. SANGUINEAE. 
Spores yellow. 
Taste mild. 
Wounds of lamellae becoming gray or blackish. 4 KIX. DeEcoLoRANtEs. 
Wounds of lamellae not becoming gray or blackish. 
Lamellae equal, simple. 
Pileus yellowish. XVIII. Luteak. 
Pileus some shade of red, or red and yellow inter- 
mingled, or gray and umber. 
Spores pale-yellow. XXII. INTEGRAE. 
Spores ochraceous. XXII. Avuraceas. 
Lamellae equal or nearly so, forking near the stipe at 
east. 
Spores pale-yellow. 
Pileus white or tinged with yellow or reddish. IX. BasrFuRCATAE. 
Pileus some shade of green. XVI. GLaucak. 
* By GERTRUDE SIMMONS BURLINGHAM. 
