III.—Rigidæ (rigidus, rigid). Page 194.
Pileus without a viscid pellicle, absolutely dry, rigid, the cuticle commonly breaking up into flocci or granules. Flesh thick, compact, firm, vanishing away short of the margin which is straight (never involute), soon spreading, and always without striæ. Stem solid, at first hard, then softer and spongy. Gills, a few dimidiate, others divided, rigid, dilated in front and running out with a very broad, rounded apex, whence the margin of the pileus becomes obtuse and is not inflexed. Exceedingly handsome, but rather rare.
IV.—Heterophyllæ (R. heterophylla, the typical species
of the section). Page 198.
Pileus fleshy, firm, with a thin margin which is at first inflexed, then expanded and striate, covered with a thin adnate pellicle. The gills consist of many shorter ones mixed with longer ones, along with others which are forked. Stem solid, stout, spongy within.
V.—Fragiles (fragilis, fragile or brittle). Page 201.
Pileus more or less fleshy, rigid-fragile, covered with a pellicle which is always continuous, and in wet weather viscid and somewhat separable; margin membranaceous, at first convergent and not involute, in full-grown plants commonly sulcate and tubercular. Flesh commonly floccose, lax, friable. Stem spongy, at length wholly soft and hollow. Gills almost all equal, simple, broadening in front, free in the pileus when closed. Several doubtful forms occur. R. integra is specially fallacious from the variety of its colors.
[*] Gills and spores white.
[**] Gills and spores white, then light-yellowish or bright lemon-yellowish.
[***] Gills and spores ochraceous.