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

LECCINUM

199

and when cut developing a faint flush of vinaceous but the change not
progressing to gray and no gray showing on dried basidiocarps, borders
of larval tunnels merely pallid-brown, becoming olive-yellow in the base
of the stipe in age and yellow persisting to some extent in dried material, FeS04 bluish; NH4OH on flesh no reaction.
Tubes 1-1.5 cm long, depressed around the stipe, pallid when
young, becoming dingy bister; pores pallid at first, when bruised staining
dingy yellowish cinnamon, small (1-2 per mm), round.
Stipe 6-10 cm long, 1-2 cm thick at apex, solid, color changes as
described above for context, surface ornamented by fine brown points
and the ground color more or less grayish avellaneous shading to pallid
at apex and base, base with white mycelium.
Spore deposit dark cinnamon-brown; spores 15-19 (20) X 5-7 gt,
smooth, with a minute apical thin spot, more or less fusoid in face view,
in profile somewhat inequilateral, wall 0.5 u thick as revived in Melzer's;
color in KOH ochraceous to yellowish cinnamon, in Melzer's pale tawny.
Basidia 4-spored, hyaline in KOH, clavate. Pleurocystidia-none
seen except near the pores, 20-36 X 8-12 p, content hyaline to ochraceous, fusoid-ventricose with subacute apex, smooth, thin-walled. Cheilocystidia clavate or similar to pleurocystidia. Caulocystidia 35-50 (60) X
10-18 /, thin-walled, clavate to ovate-pedicellate or elliptic-pedicellate,
more rarely somewhat fusoid or mucronate, content mostly pale dull
cinnamon as revived in KOH, walls thin and even.
Tube trama of weakly divergent hyphae, hyphae tubular, thinwalled and 4-6, wide, some large laticiferous elements with dull cinnamon amorphous content also present; in Melzer's numerous nearly hyaline globules present in the mount. Pileus cuticle of appressed narrow
(3-6, wide) hyphae with septa widely spaced, the cells not disarticulating, content cinnamon in KOH and slowly forming indistinct globules
in Melzer's nearly all hyphae with cinnamon pigment globules 2-6, in
diameter. Hyphae of subcutis and the adjacent context hyphae hyaline
to yellowish in Melzer's. Clamp connections absent.
Habit, habitat, and distribution.-Scattered in aspen-birch woods
near Brimley, Chippewa County, July 11, 1968, H. D. Thiers (Smith
75536).
Observations.-This is one of the most striking and distinct species
of Leccinum known. The strong tendency for pigment globules to form
in Melzer's in mounts of the cuticular hyphae, the narrowness of these
hyphae, the lack of color in the subcutis and the adjacent context
hyphae-also as revived in Melzer's-the color change to vinaceous in
fresh basidiocarps and the fact that it does not continue on to become