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

BOLETELL US

385

becoming somewhat olivaceous; pallid to pinkish in the space between
the areolae. Context pale to bright yellow, soon deep blue when injured,
odor none, taste acid; with KOH orange, with FeS04 yellow changing to
dingy ochraceous slowly.
Tubes 8-12 mm deep, depressed around the stipe, yellow changing
to blue, with decurrent lines down the apex of the stipe; pores wide and
angular (1-1.5 mm in diameter), yellow but blue and then brown from
injury.
Stipe 6-9 cm long, 9-14 mm thick, equal, solid, within streaked
ochraceous and pallid, soon blue where injured; surface red-pruinose to
scurfy, about concolorous with pileus or apex yellow, base coated with
a dingy honey-yellow mass of soft mycelium.
Spore deposit dark olive-fuscous; spores 11-14 X 5.5-7 (8) g; in
face view subelliptic, in profile broadly somewhat inequilateral, suprahilar depression broad and often inconspicuous, ornamented with 9-12
sublongitudinal ridges (about as in B. chrysenteroides) and with an
apical break in the outer wall in the form of a slit, in KOH bright pale
amber-brown or more ochraceous, in Melzer's nearly "Brussels-brown"
(a dark yellow-brown) or more dingy and many showing a distinct
bluish gray shadow when first revived.
Basidia 4-spored, clavate, 20-26 X 8-9 p, soon disintegrating in 2 percent KOH, pale yellow in Melzer's and outlines remaining distinct. Pleurocystidia abundant 36-48 X 9-13 u, fusoid-ventricose with a long neck
and subacute apex, hyaline in KOH, in Melzer's having a dark dingy
yellow-brown granular content variously dispersed. Pileus cutis a trichodermium of hyphae 8-12, in diameter with dark orange-brown content
in Melzer's but no amyloid granules present, walls smooth, thin, usually
with a constriction at the septa, end-cells tubular and rounded at the
tip or clavate and up to 15 u or more broad. Clamp connections none.
Habit, habitat, and distribution.-Scattered under beech and other
hardwoods on low ground near Manchester, September 15, 1961, Smith
64264 (type), and from near Ann Arbor.
Observations.-The field characters would lead one to place it in
the Boletus fraternus group. It differs from Boletellus chrysenteroides in
the copious honey-yellow mycelium around the base of the basidiocarps
and in the red of the pileus as well as a quicker and more intense blue
reaction when injured.