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

BOLETUS

297

155. Boletus amarellus Quelet
Assoc. Fr. Av. Sc. 1882:398
Illus.P1. 115(upper).
Pileus 3-10 cm broad, convex, becoming broadly convex, margin
even; surface dry but soft to the touch and tacky when wet (subviscid),
aull cinnamon to reddish cinnamon or finally vinaceous-red ("vinaceous-rufous" to "Dragon's blood-red"), drying dull ochraceous-brown
to dull cinnamon. Context yellow, developing a vinaceous-red zone near
the tubes, taste slowly peppery, with FeSO4 negative, odor slightly acid.
Tubes up to 1 cm deep in large caps, dull ochraceous to buckthorn-brown, not staining blue if injured; pores at first 1-2 per mm but
in age up to 2-3 mm broad, angular, yellow-brown young but becoming
reddish cinnamon or redder in age; not staining blue if injured.
Stipe (3) 4-8 cm long, 5-10 mm thick, equal, interior lemonchrome in lower half, surface. streaked with reddish cinnamon fine
fibrils, base coated with bright yellow mycelium, apex ornamented with
decurrent lines from the tubes.
Spore deposit pale dull cinnamon; spores 9-11 X 3-4 g, smooth,
apical pore not distinct, shape in profile obscurely inequilateral, the
suprahilar area flattened, in face view subfusiform, color in KOH dingy
olivaceous becoming bright olive-yellow, in Melzer's many becoming distinctly dextrinoid, wall about 0.2 pi thick.
Basidia 4-spored, 22-30 X 7-9 u, yellowish in KOH and more
ochraceous in Melzer's. Pleurocystidia 36-68 X 6-9,, subcylindric and
usually curved near the apex, smooth, content homogeneous and ochraceous in either KOH or Melzer's, wall thin and smooth. Cheilocystidia
32-60 X 4-7 u, otherwise like the pleurocystidia. Caulocystidia versiform: (a) elongate-clavate and 38-65 X 3-4 X 5-7u;;(b) fusoid-ventricose and 28-42 X 7-12 g, apex obtuse; (c) some subcylindric like the
cheilocystidia; all types smooth, thin-walled, and content not distinctive
in KOH or Melzer's.
Cuticle of pileus basically a tangle of hyphae 6-12 (15) l wide,
cells mostly elongate but some short ones present, walls thin, smooth,
hyaline, content yellowish, cells tubular to slightly inflated, in large caps
some hyphae 30 p or more wide and the cells inflated as well as having
the cells disarticulating to a distinct degree leaving ellipsoid cells free in
the mount; end-cells clavate to fusoid or cylindric, 10-20 (30) u wide
and up to 200 Ju long. Context hyphae with orange-red content in some
as viewed in Melzer's. Cuticular hyphae merely ochraceous in Melzer'sno evidence of emulsification of the content. No clamp connections
observed.