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

LECCINUM

177

Context white, scarcely changing when sectioned, slowly bluish with
FeSO4, odor none, taste mild.
Tubes pallid, depressed around the stipe, staining avellaneous
where bruised; pores small, whitish, staining yellowish to brownish and
when severely bruised staining wood-brown.
Stipe about 7 cm long and 1 cm thick near apex, whitish and with
very fine dark brown punctation, lower part faintly yellowish in places
but no blue to blue-green stains present, solid, when sectioned the
cortex pinkish tan, fuscous-brown around wormholes (probably changing
slowly when cut), pallid in the base.
Spores 14-20 X 44.5 (5) u, smooth, elongate-subfusiform in face
view, in profile elongate-subfusoid, the suprahilar depression very shallow and broad (almost absent in some), pale clay color and tawny singly
and in masses respectively as revived in KOH, scarcely changing color in
Melzer's, wall very slightly thickened and no apical differentiation visible.
Basidia 4-spored, 18-26 (35) X 10-14 g, clavate, hyaline to ochraceous in KOH, with some refractive granular material, yellowish in
Melzer's. Pleurocystidia scattered, 38-56 X 9-14 u, fusoid-ventricose,
apex subacute, content hyaline to smoky ochraceous from dissolved pigment. Cheilocystidia mostly resembling basidioles but many more with
ochraceous content. Caulocystidia fusoid-ventricose and of two subtypes,
40-70 X 15-25 ju and with relatively short neck, and 45-70 X 8-14 L
with a long tapered neck, both types with smoky ochraceous content
and smooth walls.
Pileus trichodermium of tangled smooth, thin-walled filaments
5-12l wide with end-cells somewhat cystidioid and hyaline to ochraceous, content in KOH or Melzer's, homogeneous. Subcutis of interwoven hyaline subgelatinous hyphae 4-7 p wide. Context hyphae 8-15 A
wide and strongly orange to orange-red in Melzer's toward the subcutis
and paler away from it. Clamp connections absent.
Habit, habitat, and distribution.-Under birch, St. Ignace, Mackinac
County, July, apparently rare.
Observations.-This species is distinct by reason of the long narrow
spores and the slowly changing context. It is most closely related to L.
flavostipitatum, but the spores are longer and the pileus is much paler in
color.