=R. cyanoxan´tha= (Schaeff.) Fr. _Gr_—blue; _Gr_—yellow. (From the colors.) (Plate XLIV, fig. 1, p. 184.) =Pileus= 2–3 in. and more broad, _lilac or purplish then olivaceous-green_, disk commonly becoming pale often yellowish, _margin_ commonly becoming _azure-blue or livid purple_, compact, convex then plane, then depressed or infundibuliform, sometimes even, sometimes wrinkled or streaked, viscous, margin deflexed then expanded, remotely and slightly striate. =Flesh= firm, cheesy, white, commonly reddish beneath the separable pellicle. =Stem= 2–3 in. long, as much as 1 in. thick, _spongy-stuffed_, but firm, often cavernous within when old, equal, smooth, _even_, shining white. =Gills= rounded behind, connected by veins, not much crowded, broad, forked with shorter ones intermixed, shining white. Allied to R. vesca in its _mild_, pleasant _taste_ and in other respects, but constantly different in the color of the pileus, which is very variable, whereas in R. vesca it is unchangeable. The peculiar combination of colors in the pileus, though very variable, always readily distinguishes it. _Fries._ =Spores= 8–9µ, cystidia numerous, pointed, _Massee_; 8–10×6–8µ _Sacc._ In mixed woods. Common. August to October. Pronounced one of the best esculent species by all authorities. =R. heterophyl´la= Fr. _Gr_—differing; _Gr_—a leaf. (Gills differing in length.) =Pileus= very variable in color, but _never becoming reddish or purple_, fleshy, firm, convexo-plane then depressed, _even, polished_, the very thin pellicle disappearing, margin thin, even or densely but slightly striate. =Flesh= white. =Stem= solid, firm, somewhat equal, _even_, shining white. =Gills= _reaching the stem in an attenuated form, very narrow, very crowded_, forked and dimidiate, shining white. Taste _always mild_, as in R. cyanoxantha, from which it differs in its smaller stature, in the pileus being thinner, even, _never reddish_ or purplish, with a thin closely adnate pellicle, in the _stem being firm and solid_, and in the _gills_ being _thin, very narrow, very crowded_, etc. The apex of the stem is occasionally dilated in the form of a cup, so that the gills appear remote. _Fries._ =Spores= echinulate, 5×7µ _W.G.S._; 7–8µ diameter _Massee_. Common. Woods. July to November. Edible, of a sweet nutty flavor. _Stevenson._ R. heterophylla is very common. Its smooth, even pileus, colored in some dingy shade of green, distinguishes it. It is much infested by grubs. Specimens for the table should be young and fresh. Wilted specimens are unpleasant.