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

SUILL US

61

Spore deposit dull cinnamon when moisture has escaped; spores
6.6-8.8 X 2.5-3 iu, thin-walled, greenish hyaline in KOH, yellowish in
Melzer's, oblong in face view, oblong to obscurely inequilateral in profile, with 1-2 oil drops.
Basidia 15-20 X 4.4-6.6 u, clavate, sterigmata about 2.5 Ai long,
4-spored, content hyaline in KOH. Pleurocystidia 26-35 X 8-11 u,
clavate, hyaline in KOH or content dingy yellow-brown, rare, in fascicles
mostly near tube edge and with dingy yellow-brown incrusting pigment
surrounding the bundle at the level of the hymenium. Cheilocystidia
similar to pleurocystidia but as dried having more yellow-brown content
and more amorphous pigment present at the level of the basidia, or the
tube edge entirely of short, clavate, colored to hyaline cells. Caulocystidia 30-50 X 7-10 i, in fascicles, clavate to narrowly fusoid, some
with bister content, some hyaline to pale ochraceous, with heavy deposits of dark rusty brown pigment around the bases of the bundles.
Caulobasidia in a hymenium with a gelatinous subhymenium. Clamp
connections absent.
Tube trama of a central strand of brownish to hyaline parallel
hyphae 4-7, in diameter, with hyaline somewhat divergent and gelatinous hyphae leading to the hymenium, content hyaline to brownish in
Melzer's. Pileus with a gelatinous epicutis of interwoven hyphae 2-6 i in
diameter, dingy ochraceous in KOH. Clamp connections absent.
Habit, habitat, and distribution.-Not uncommon during late summer and fall under pine, mostly white pine, in natural stands or in
plantations where it is very abundant at times.
Observations.-S. albidipes is featured by the pale colors and the
cottony pallid material making up the false veil. The spores are among
the smallest in the genus. This species has frequently been confused with
S. granulatus, but the false veil quickly distinguishes S. albidipes from
the latter if young basidiocarps are available. In old ones the pileus of S.
granulatus is typically a darker rusty cinnamon. The problem with S.
albidipes centers around related western taxa with basically the same
type of veil but with other distinguishing features, see Smith & Thiers
(1964).
Material examined.-Cheboygan: Smith 67678. Livingston: Smith
64747, 75209, 75216. Luce: Smith 58179. Marquette: Bartelli 2442.
Washtenaw: Kauffman 10-7-24, 10-8-24; Smith 66419; Thiers 4542.