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

LECCINUM

203

fairly viscid, glabrous and often with depressions in age, grayish brown
to dull yellow-brown and often flushed olivaceous in age. Context white,
when cut not staining or slowly becoming slightly brownish (near
"pinkish buff"); odor and taste mild.
Tubes 8-15 mm deep, pallid, slowly becoming wood-brown as
spores mature, deeply depressed around the stipe; pores small, pallid
then concolorous with the sides and either not staining when bruised or
staining yellow.
Stipe 7-12 (15) cm long, 7-12 (16) mm thick above, evenly enlarged downward, with dark brown to blackish punctate to nearly reticulate or squamulose decorations, the pallid ground color visible, solid,
white within, slowly staining pinkish buff in the cortex when sectioned,
also developing both blue and red stains in restricted areas lower down
if wet.
Spores 15-19 X 5-7 u., smooth, subfusiform in face view, in profile
ventricose-inequilateral to elongate-inequilateral, often with a pronounced suprahilar depression, pale tawny singly, in groups darker (both
as revived in KOH), pale tawny in Melzer's, wall thickened to about
0.5 Mt as revived in KOH.
Basidia 4-spored, 11-13 ji broad, hyaline in KOH and yellowish in
Melzer's. Pleurocystidia-none observed. Caulocystidia mostly clavate,
32-46 X 9-17 gt, with smoky ochraceous content in KOH, some with an
apical protrusion causing the cell to be clavate-mucronate and a few
varying to fusoid-ventricose.
Pileus cuticle a tangled layer of floccose hyphae 6-12 (15) u wide,
above a subgelatinous subcutis, their content smoky ochraceous in KOH
and with a grayer shadow in Melzer's but content remaining granular to
homogeneous, wall at first seen to be enveloped in an outer gelatinous
matrix as observed revived both in KOH or in Melzer's, the layer or
matrix of irregular extent and thickness but at times enveloping two
adjacent hyphae, this material slowly dissolving in KOH, at times a few
short slightly inflated cells observed. Clamp connections absent.
Habit, habitat, and distribution.-Not uncommon throughout the
state during the summer and fall under birch.
Observations.-The dingy yellow-brown to grayish brown pileus, the
failure of sectioned basidiocarps to stain gray, and the broad spores are
characteristic of this, the type form, of the L. scabrum complex. On the
basis of the species as presently defined it has been one of the most
frequently misidentified species in North America. It is not possible at
this time to present a complete study on this subsection either for