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

LECCINUM

149

Habit, habitat, and distribution.-Gregarious under aspen and birch,
lower Maple River, Emmet County, July 12, 1968, Smith 75560.
Observations.-This appears to be an extreme variant as regards the
development of fibrillose squamules on the pileus which impart a tawny
color to the pileus-a color much richer than the dingy cinnamon of the
type variety. In addition the base of the stipe did not stain brown when
handled.
71. Leccinum laetum Smith, Thiers, & Watling
Mich. Bot. 5:154. 1966
Pileus 5-15 cm broad, oval to convex, expanding to broadly
obtuse to broadly convex, margin appendiculate; surface dry and
appressed fibrillose-squamulose, becoming glabrous; color when young
and fresh orange to orange-ochraceous but becoming dull ochraceous,
the appressed fibrils or squamules yellow-brown ("buckthorn-brown"),
glabrescent and in age subviscid and at this time with olive tones
on the margin and the disc dingy ochraceous to dull orange-brown.
Context pallid, when cut soon staining vinaceous then gray and then
fuscous; in the stipe staining in addition blue and yellow and reddish
(in different areas), FeSO4 blue; KOH on cutis no reaction to slightly
rusty brown; odor none, taste mild to slightly acid.
Tubes 1-2 cm deep, depressed around the stipe to nearly free,
white staining avellaneous when cut; pores minute, round, white to
olive-white when young, staining olive when slightly bruised, but when
severely bruised staining near grayish vinaceous-brown (near "woodbrown").
Stipe 8-16 cm long, 1-2.5 cm thick, equal, solid, when cut changing color as noted under context above, soon fuscous-black around the
larval tunnels; surface faintly ornamented by pallid then brownish and
finally darker points, lines, or squamules, apex pallid, viscid over the
base when young as in Boletellus russellii.
Spore deposit olive when wet and olive-brown when air-dried
("dark olive-buff" to "olive-brown"); spores 13-16 (17) X 4-5,,
smooth, wall slightly thickened, shape in profile somewhat elongatedinequilateral with a broad shallow suprahilar depression, in face view
subfusoid, pale ochraceous in KOH, in Melzer's a few dextrinoid, the
rest pale yellow-brown (in mounts made from hymenial tissue when
revived in Melzer's showing a faint suggestion of the fleeting-amyloid
reaction).