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

366

THE BOLETES OF MICHIGAN

Stirps INSUETUS
198. Boletus chippewaensis Smith & Thiers, sp. nov.
Pileus 12-16 cm latus, pulvinatus, glaber, subviscidus citrinus
demum ferrugineo-maculatus vel vinaceo-fulvus, demum lateritius. Contextus albidus. Tubuli pallide lutei; pori lutei tactu subcaerulei. Stipes
6-10 cm longus, 2.5-3.5 cm crassus, pallide alutaceus, albo-reticulatus.
Sporae 11-16 X 5-7;. Specimen typicum in Herb. Univ. Mich. conservatum est; prope Sugar Island, July 31, 1965, legit Smith 71914.
Pileus 6-7 cm broad when young, expanding to 12-16 cm when
mature, convex, pulvinate or broadly convex; surface glabrous, slightly
viscid but soon dry, pale lemon-yellow splashed irregularly with ferruginous to vinaceous-tawny, finally brick-red overall or margin remaining pale yellow. Context thick, firm, white, slowly becoming dingy tan
beneath the cuticle after sectioning, odor and taste pleasant but hardly
distinctive; olive-gray with FeSO4; with KOH no reaction.
Tubes pale greenish yellow ("primuline-yellow"), free or nearly so,
in age olive-ochraceous to olive-brown; pores "primuline-yellow," staining vinaceous-cinnamon when bruised, about 1-2 per mm at maturity.
Stipe bulbous to equal, 6-10 cm long, 2.5-3.5 cm thick at apex,
solid and white throughout, scarcely staining when cut; surface dingy
pinkish buff to cinnamon-buff beneath a white reticulum, base whitish.
Spores 11-16 X 5-7 u, smooth, no apical pore evident, in face
view mostly broadly fusoid, in profile inequilateral with 'the suprahilar
depression rather distinct, in KOH greenish ochraceous, in Melzer's pale
dingy yellow-brown (no dextrinoid spores seen), wall about 0.2, thick.
Basidia 4-spored, 26-30 X 7-10 g, clavate, hyaline in KOH, weakly
yellowish in Melzer's. Pleurocystidia rare to scattered, narrowly fusoid,
34-46 X 6-10 I, hyaline in KOH and Melzer's. Cheilocystidia intergrading with basidioles, 18-30 X 7-9 u, content yellowish in KOH but
fading to hyaline.
Pileus cuticle a short trichodermium arising from a layer of gelatinous interwoven hyphae, the turf elements gelatinizing-as revived in
KOH, with thickish refractive walls irregular in outline and with some
debris adhering, not sharply defined as revived in KOH, in Melzer's the
content yellowish and walls apparently soon disintegrating, the apical
cell 10-22 X 6-12 jL broad (approximately) and clavate to mitten-shaped,
subcuticular hyphae with orange-brown content. Context hyphae hyaline
and interwoven, many large laticiferous hyphae up to 15 wide and
yellow in KOH present. Clamp connections absent.
Habit, habitat, and distribution.-Scattered under mixed conifers
and hardwoods, Sugar Island, July 31, 1965, Smith 71914.