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

LECCINUM

209

Habit, habitat, and distribution.-Scattered to gregarious alohg
roads in slashings through hardwood forests with scattered yellow birch
in them but with heavy yellow birch reproduction along the roads,
common, late summer and fall in the Upper Peninsula.
Observations.-The distinguishing features of this Leccinum are the
caulocystidia as described, the yellow stains which develop over the
pileus margin and the bruised pores, the broad spores, and the almost
moniliform appearance of many of the epicuticular hyphae on young
pilei. The inflated cells of the cuticular hyphae, the broader spores, and
change to red when bruised or sectioned, distinguish the species from L.
flavostipitatum. L. oxydabile Singer is a paler species with different
caulocystidia (see Watling, 1968).
106. Leccinum oxydabile (Singer) Singer
Amer. Midl. Nat. 37:123. 1947
Krombholtzia oxydabilis Singer, Schwiz. Zeitschr. Pilzk. 16:136. 1938.
Pileus 2.5-3 cm broad, convex, the margin fertile and even, white
when fresh and young but soon becoming somewhat yellowish to buff
to pinkish buff or pale crust-brown from handling or on aging, appressedfibrillose becoming glabrous but dry to the touch. Context white, when
sectioned staining pinkish buff under the subcutis and pale vinaceous in
the region of the stipe apex, pea-green to bluish green with FeSO4, odor
and taste mild.
Tubes ventricose, about 10 mm deep, depressed to practically free
around the stipe, snow-white when young, staining cream-buff after
cutting; pores white, minute, staining ochraceous when bruised.
Stipe 6-7 cm long, 8-10 mm at apex, 12-13 mm at base, with very
fine ornamentation which is white at first, darkening over the lower
two-thirds to avellaneous and on drying yellowish over the basal third,
base blue where handled, solid, watery-streaked on the cut surface,
pallid but slowly staining vinaoeous (not becoming gray, however).
Spores 15-21 X 5-6.5 u, smooth, in face view bluntly fusiform, in
profile elongate-inequilateral, suprahilar depression shallow and indistinct, dingy ochraceous and pale tawny singly or in groups respectively
as revived in KOH, not changing significantly in Melzer's; wall somewhat
thickened and apex with a pallid minute spot but not a true pore.
Basidia 4-spored, 26-32 X 10-13 J, hyaline in KOH, with globules
of various sizes in the interior, hyaline in Melzer's. Pleurocystidia
scattered, 48-75 X 9-16,j, fusoid-ventricose with prolonged narrow neck