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

LECCINUM

169

81c. Leccinum insigne f. ochraceum
Pileus 5-10 cm broad, convex becoming broadly convex, margin
appendiculate at first, surface dry and nearly glabrous to thinly fibrillose
with sparse grayish fibrils, yellow to orange-yellow overall, dry at first
but subviscid in age. Context firm at first, lax in age, whitish, staining
avellaneous and then fuscous when cut. Odor and taste mild.
Tubes about 1.5 cm deep, soon depressed around the stipe,
whitish when young, when cut the exposed surface weakly yellow (in
the white state), near bister-brown when mature; pores pallid at first,
when lightly bruised staining yellowish.
Stipe 9-14 cm long, 1-2 cm thick, equal or nearly so, solid,
whitish but soon fuscous on cut surface; stipe ornamentation fine, pallid
when young but soon blackish brown and drying blackish.
Spores 11-14 X 4-4.5 #, smooth, inequilateral in profile, subfusiform in face view. Pileus cutis of appressed hyphae 6-10 (15), wide,
cells frequently disarticulating, walls smooth or ornamented as in var.
insigne f. insigne, end-cells bullet-shaped to cystidioid, short cells not
infrequent in the wider hyphae, content ochraceous in KOH, in Melzer's
granular or as beads up to 1.5 p in diameter. Hyphae of subcutis
orange-red in Melzer's.
Habit, habitat, and distribution.-Scattered under aspen-birch,
northwest Montmorency County, September 7, 1967, Smith 75113.
Observations.-This variant is readily confused with L. ochraceum
but it does not stain reddish on the cut flesh before changing to fuscous. The content of the cuticular hyphae was not olivaceous as revived
in KOH and no violaceous-brown laticiferous elements were observed in
any part of the basidiocarp when portions were mounted in Melzer's. It
appears to us to be similar to f. insigne in all essentials except the lack
of red pigment in the cuticular hyphae.
81d. Leccinum insigne f. obscurum
Pileus 6-12 cm broad, convex expanding to plane, the sterile
margin breaking into segments, surface spotted or streaked with obscure
patches of fibrils, glabrous in age, subviscid at maturity, a dull orangebrown. Context soft, pallid, when cut staining lilac to grayish and then
fuscous (lacking a preliminary red stage), odor and taste not distinctive,
the FeSO4 reaction grayish.
Tubes 1-2 cm deep, depressed around the stipe, white then olivaceous-gray, when cut slowly staining fuscous; pores minute, whitish, pale