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

BOLETUS

329

Subsection RETICULATI, subsect. nov.
Stipes reticulatus; pleurocystidia cum "KOH" valde lutea.
Typus: Boletus griseus.
Stirps GRISEUS
KEY
1. Tubes yellow when young, staining orange-brown.......... B. oratipes
1. Tubes white when young; staining brown when injured......... B. griseus
177. Boletus oratipes Peck
Ann. Rept. N. Y. State Mus. 29:67. 1878
Illus. P1. 131.
Pileus 4-16 (20) cm broad, obtuse to convex, the margin bent in
slightly or straight, expanding to broadly convex or nearly plane; surface
dull and unpolished to velvety or minutely tomentose, when moist subviscid to the touch; color when young fuscous to violaceous-fuscous
becoming dark olive-gray to olive-buff and later paler as well as developing a strong lemon tint in the ground color, at times yellow-brown in
age, at times appearing to have a slight yellowish pruina. Context thick,
chrome-yellow, odor none, taste slightly bitterish, with FeSO4 no reaction, with KOH bleaching the yellow to a paler tone or whitish but in
the stipe causing a change to dingy brown.
Tubes lemon-yellow staining orange-yellow, adnate to subdecurrent, rarely depressed, 5-8 (10) mm deep; pores small about 2 per mm
round, lemon-yellow staining orange-brown when injured.
Stipe 8-15 cm long, 1-2 (3.5) cm thick above, equal to narrowly
clavate, solid, chrome-yellow throughout, becoming darker orangechrome where injured (finally dingy yellow-brown); surface laceratereticulate to base or merely-sublacerate to reticulate, yellow overall. Veil
absent.
Spore deposit olive-brown to near bister (dark yellow-brown);
spores 9-13 X 3-4 t, smooth, walls slightly thickened, dingy pallid
yellow in KOH or a few ochraceous, in Melzer's pale orange-tan, in
profile narrowly inequilateral with a broad suprahilar depression, in face
view narrowly oblong to slightly ventricose with apex obtuse.
Basidia 4-spored, 22-30 X 6-8 u, hyaline to yellowish in KOH.
Pleurocystidia abundant, 38-65 X 9-15 u, ventricose at base with a