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

LECCINUM

219

Habit, habitat, and distribution.-This species is apparently very
rare in North America. Our description was taken from material found
at the Ypsilanti golf course, Washtenaw County, September 15, 1961. It
grew under oak on rather hard-packed soil.
113. Leccinum luteum Smith, Thiers, & Watling
Mich. Bot. 6:114. 1967
Illus. P1. 91.
Pileus 3-6.5 cm broad, convex to obtuse when young, remaining
merely obtuse in age, glabrous, subviscid, alveolate, or smooth and even,
becoming areolate-rimose, pale yellow, becoming olive-brown in age, on
drying becoming nearly date-brown, with KOH orange-cinnamon to pale
red. Context thin, soft, pallid or flushed yellow near the trichodermium,
staining vinaceous-gray to avellaneous when sectioned; slowly olive with
FeSO4, odor none, taste acidulous or mild.
Tubes ventricose, up to 15 mm deep, deeply depressed around the
stipe to nearly free, pallid to pale gray to fuscous; pores on old pilei
about 2-3 per mm (small), pallid when young, slowly becoming olivebuff and when injured avellaneous or wood-brown.
Stipe 6-13 cm long, 8-10 mm thick at apex, 10-15 (17) mm at
base, nearly equal, pallid and solid, cut surface in lower portion staining
pale green in local areas and fuscous overall slowly, dark blue with
guaiac; surface pallid above, pale yellow below, ornamentation present as
sparse fine blackish points and squamules.
Spore deposit olive-brown; spores 17-20 X 5-6.5 u, smooth, no
apical differentiation visible or merely as a thin spot, in face view subfusoid, in profile elongate-inequilateral, dull yellow-brown to dingy clay
color in KOH, nearer ochraceous-tawny in Melzer's but not dextrinoid,
wall about 0.5 gt thick as measured in Melzer's, slightly thicker revived in
KOH.
Basidia 18-20 X 10-14 g, near tube mouths 25-30 X 10-15 pI near
pileus context, clavate, content homogeneous in KOH or with a large
hyaline globule, merely yellowish in Melzer's but a few with dark
yellow-brown granules. Pleurocystidia scattered, 37-52 (75) X 6-10
(12) u, fusoid to subfusoid with acute to subacute apex, smooth, thinwalled, not incrusted, content when revived in KOH homogeneous and
hyaline to pale ochraceous to ochraceous-brown, dark yellow-brown
(bister) in many when revived in Melzer's. Cheilocystidia similar to the
pleurocystidia but varying to subcylindric to narrowly clavate and