The boletes of Michigan, by Alexander H. Smith and Harry D. Thiers.

BOLETUS

299

Observations.-We have not encountered this species in the state.
Its diagnostic features are the subtomentose pileus, strongly dextrinoid
spores many of which reach a length of 15 Li, the abundant pleurocystidia with elongated necks,'and the red pileus and tubes. The portion
of the type studied did not show caulocystidia but more than likely
they are (when present) similar to the end-cells of the cuticular hyphae
of the pileus. The spores lack any distinctive color in KOH. It may be
of some significance to note that Peck did not mention taste in his
original account. Hence we do not know if the type was mild in taste.
157. Boletus rubritubifera Kauffman
Bull. N. Y. State Mus. 179:88. 1915
Data from original description:
Pileus 2-5 cm broad, fleshy, convex, obtuse, glabrous or obscurely
subtomentose, dry, even, cinnamon-rufous (Ridgway), slightly variegated
with yellowish. Context whitish tinged yellow, unchanged, very thick,
odor and taste mild.
Tubes Pompeian-red (Ridgway) throughout; pores red, depressed
around the stem, convex, 5-8 mm long, pores 2 per mm, subangular,
dissepiments rather thick.
Stem 5-6 cm long, 1-2 cm thick above, tapering downward, dingy
apricot-yellow (Ridgway), concolor within, even, glabrous, solid.
Data from type:
Spores 9-12 (13.5) X 3-4 g, smooth, lacking an apical pore, yellowish hyaline in KOH (not olive), remaining uncolored in Melzer's or some
slowly pale tan (weakly dextrinoid), shape in profile narrowly and somewhat to obscurely inequilateral, a few "sway-backed," in face view
narrowly subfusoid to suboblong, wall about 0.2 pu thick, rarely wavyangular in optical section.
Basidia 4-spored, clavate, up to 35 X 11 l, not distinctively
colored in either KOH or Melzer's. Pleurocystidia 36-68 X 7-14 u, narrowly fusoid-ventricose varying to almost subcylindric, walls thin and
smooth, content not distinctive in either KOH or Melzer's. Cheilocystidia similar to but smaller than the pleurocystidia. Caulocystidia
35-70 X 4-7,u, some almost seta-like but thin-walled, mostly subcylindric to flexuous with obtuse apex (resembling end-cells of the cuticular
hyphae of the pileus; color not distinctive in Melzer's.
Cuticle of pileus of interwoven matted-down hyphae 4-7 u wide,
with end-cells appressed or ascending, the filaments tubular and the cells
long, walls smooth, thin, a few with a thin gelatinous halo, content