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

LECCINUM

217

Basidia 4-spored, 24-30 X 10-12 g, clavate, yellowish in both KOH
and Melzer's, mostly with a homogeneous content. Pleurocystidia 36-48
X 9-13 j, fusoid-ventricose with more or less obtuse apex, thin-walled,
hyaline, smooth, content yellow at first but the pigment diffusing into
the mount, not distinctive in either KOH or Melzer's. Cheilocystidia
similar to pleurocystidia or with apex more acute, many yellowish in
KOH. Caulocystidia 35-70 X 7-15 u, fusoid-ventricose to mucronate,
thin-walled, smooth, content hyaline to yellow-brown as revived in KOH;
brachybasidioles also present and intergrading with the caulocystidia.
Hymenophoral trama of the bilateral Boletussubtype, the hyphae
with yellow content when revived in KOH but pigment diffusing into
the mounting medium; subhymenium cellular to filamentose. Pileus
trichodermium more or less cellular and consisting of enlarged hyphal
cells with the upper 3-6 cells of the filament subglobose and the largest
10-25 (30) i in diameter, the ultimate and penultimate cells often
greatly reduced in size and cystidioid in shape (10-30 X 7-14 i) or at
times almost reduced to a papilla on the end of the trichodermial element, the third and fourth cells back usually the largest, all of them
thin-walled, smooth, yellow in KOH but soon fading and in Melzer's
with reddish orange to orange-brown content. Context of inflated thinwalled hyphae "empty" as revived in KOH and Melzer's or a few of the
hyphae with ochraceous to orange content; laticiferous elements occasional, (4) 6-12 (15) i wide. Clamp connections absent.
Habit, habitat, and distribution.-Solitary to gregarious in thin
grassy oak woods during wet weather in July, August, and early
September, rare in Michigan and to be expected in the lower 2 to 3 tiers of
counties in the Lower Peninsula. It is much more common southward.
Observations.-This species is most closely related to L. crocipodium, but the latter differs in wider spores and a less cellular cuticle.
From B. subglabripes it is readily distinguished by the resinous feel of
the stipe and the darkening stipe ornamentation.
112. Leccinum.crocipodium (Letellier) Watling
Trans. Bot. Soc. Edinb. 39:200. 1961
Boletus crokipodius Letellier, Champ. P1. 666. 1838.
Pileus 4-7.5 cm broad, obtuse expanding to convex or the margin
finally flaring, the margin obtuse when young, not viscid but the surface
with a resinous feel, soon becoming irregularly rimose, very rugulose to
pitted, the prominences soon blackish brown, the valleys mottled with