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

LECCINUM

187

handled but in drying a few yellowish areas show on the pallid ground
color at or near the base, solid, white within at the apex, staining
vinaceous to fuscous when stipe is sectioned.
Spores 13-16.5 X 4-5 /, smooth, pale clay color singly and pale
tawny in groups as revived in KOH, pale tawny revived in Melzer's,
narrowly subfusiform in face view, obscurely elongate-inequilateral in
profile, the suprahilar depression obscure, wall only slightly thickened
and with no apical pore.
Basidia 4-spored 20-26 X 10-12 u, clavate, hyaline, and usually
with a large oil drop when revived in KOH. Pleurocystidia variable,
essentially fusoid-ventricose, 50-70 X 9-13 p, near the pores 30-45 X
7-11 /u, filaments resembling pseudocystidia (but lacking granular content) also present, content of all types hyaline to ochraceous. Cheilocystidia clavate to fusoid-ventricose, 20-34 X 6-10 u, brighter ochraceous than pleurocystidia when revived in KOH. Caulocystidia 40-90 X
9-22 ju, fusoid-ventricose to ventricose-mucronate, with pale smoky
brown content in KOH, typically with a proliferated neck. Caulobasidia
mostly 7-9 u broad (narrower than hymenial basidia and with colored to
hyaline content).
Hyphae of the trichodermium of the pileus consisting of tubular
thin-walled often disarticulating cells 5-12 u wide or some cells near or
including the terminal cell somewhat inflated, walls mostly smooth but
some with incrusting pigment and on standing in KOH a tendency for
blisters to develop on the outer wall, content smoky brown in KOH and
near bister in Melzer's (in the latter also showing a tendency to form
globules or become stringy), terminal cells cystidioid and those on the
broadest hyphae somewhat bullet-shaped. Context hyphae below the
subcutis yellow or orange-red in Melzer's from the colored homogeneous
content. Clamp connections absent.
Habit, habitat, and distribution.-In mixed second-growth hardwoods with birch present, Sugar Island, July and August, not common.
Observations.-In a sense L. murinaceo-stipitatum is the counterpart of L. flavostipitatum, but it stains fuscous and has a gray stipe. It
differs from L. subleucophaeum in its narrower spores. In another
closely related species, L. griseonigrum, the pores stained yellowish instead of olive, the pallid ground color of the stipe was readily visible
between the elements of the ornamentation, and no red stage was observed in the change of the flesh to gray or fuscous when it was cut. As
far as is known, the latter is associated with aspen.