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

BOLETUS 371
latter 8-14 u wide, length variable, the cells in the trichodermial elements short to long (2, 3, 4, or more times longer than broad but not
inflated). Hyphae of subcutis and adjacent context merely with yellowish walls in Melzer's. Clamp connections absent.
Habit, habitat, and distribution.-Gregarious to scattered under
beech-maple and some aspen intermixed, Berry Creek, near Wolverine,
Cheboygan County, August 10, 1968, Smith 75914.
Observations.-This is a very dark fungus with a velvety dry dull
pileus which becomes dingy yellow-brown in age, the stipe is as dark as
the pileus but had a fine reticulum of white to pallid lines, the spores
are distinctly amyloid at first, and the pileus cuticle is a tangled trichodermium in the cells of which occurs the dark pigment, but when
mounted in KOH the color in these cells disappears almost instantly.
Boletus aereus Fries should have a colored reticulum over the stipe.
We do not know whether its spores are amyloid or not. Singer considers
B. variipes, B. atkinsoni, B. gertrudiae, and B. nobilis as synonyms of B.
aereus. A critical study on the basis of hyphal detail and Melzer's reactions in the European members of the group is needed before worthwhile comparisons can be made with the European and American floras
in this complex.
Stirps EDULIS
KEY
1. Cuticular hyphae often with diverticulae; pileus ochraceous when young,
old, or dried..........................B. edulis var. ochraceus
1. Not as above....................................... 2
2. A fleeting-amyloid reaction absent on tissue of the hymenophore;
pileus not viscid...................... B. edulis var. clavipes
2. Not as above.................................... 3
3. Pileus dull fulvus to crust-brown................ B. edulis var. edulis
3. Pileus ferruginous to rose-red............................. 4
4. Pileus dark rose-red; pores staining light cinnamon when bruised................. B. edulis var. aurantio-ruber (Ammirati 2004)
4. Pileus ferruginous to bay-red; pores staining yellowish olive after
bruising....................... B. edulis var. aurantio-ruber