MICHIGAN ACADEMY OF SCIENCE. 87 



• 50. RUSSULA CHAMAELEONTIXA Fr. 



(The color-change Russula.) 



' PiLFATS 2-5 cm. broad, rather small, fragile, thin, piano-depressed, with a 

 viscid separable pellicle, margin even at first then striatnlate, colcr varying 

 for different pilei, mostly some shade of red, purple, etc., fading to yellowish 

 especially on disk. Flesh white, thin. Gills thin, crowded or close, 

 adnexed or almost free, eciual, rather broad, sometimes almost narrow, few- 

 forked, interspaces venose, ochraceous or ochraceous-yelloiv. Stem 2-5 cm. 

 long, 4-6 mm. thick, white, spongy-stuffed then hollow-, slender, ecjual or 

 subequal to subventricose, sometimies subclavate, even or obscurely rivulose. 

 Spores ochraceous. Taste mild. Odor none. 



Scattered or gregarious. In coniferous or mixed woods. So far only 

 reported from northern Michigan. 



Like R. integra this has to be considered at present a composite species, 

 from- which several species have, from time to time, been segregated. Ac- 

 cording to von Post, a pupil of Fries, the master himself included many 

 forms w^hich do not fit into his own description; and Romell follows the 

 Swedish tradition and refers to R. chomaeleontina all small forms with mild 

 taste and ochraceous gills not otherwise accounted for. "No subacrid 

 forms are included" whites Romell. Specimens with the caps a uniform red, 

 rose colored, purplish, lilac, etc., and accompanied with a 3-ellowish tint, 

 are always included; sometimes also, whitish faded forms must be placed here. 

 Since the limits of the species are not definitely settled in Europe, it seems 

 futile to attempt segregation in this county. There is, however, a subacrid 

 form in Michigan which had better not be included, and I will temporarily 

 refer to it as var. subacris (not published). R. ahietina differs from the above 

 in its habitat under balsam-fir, and the color of the cUsk being variegated 

 olive-green, etc. 



151. Russula abietina Pk. 



(The balsam-fir Russula.) 



' Illustrations: N. Y. State Mus. Rep. 54, 1901. PL 7, fig. 1-11. 



PiLEUs 1-2.5 cm. broad, thin, fragile, convex becoming plane or slightly 

 depressed in the centre, covered with a viscid, separable pellicle, tu])ercular- 

 striate on the thin margin, variable in color, puri)lish, greenish purple or olive- 

 green with a brown or l^lackish centre, or sometimes purplish wdth a greenish 

 centre. Flesh white. Gills narrowed toward the stem, subdistant, ecjual, 

 rounded behind and nearly free, ventricose, whitish becoming pale yellow. 

 Stem 1-2.5 cm. long, ecjual or tapering upward, stuffed or hollow, white. 

 Spores bright yellowish ochraceous, subglobose, 8-10 micr. Taste mild. 



Its place of growth is' only under balsam fir. It has been reported from 

 Michigan but the description given is that of Peck. The important charac- 

 ters seem to be the bright yellow- tinged spores. It is separable from R. 

 puellaris, "by the viscid cap, the gills rather widely separated from each 

 other and nearly free, the stem never yellowish nor becoming yellow where 

 wounded, and the spores having an ochraceous hue." 



52. Russula pusilla Pk. . 

 (The little Russula.) 



Illustrations: N. Y. State Mus. Bull. 122, 1908. PI. 110, fig. 7-14. 

 PiLEUs less than 3 cm. broad, rarely larger, very thin, convex then nearly 



