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

BOLETUS

229

KEY TO STIRPES
1. Spore deposit bright yellow-brown (about amber-brown or brighter)........................................ Stirps Affinis
1. Spore deposit duller than in above choice, usually olive to olive-brown
or dark yellow-brown.................................. 2
2. Stipe narrowed at base and firmly attached to substratum by a mat
of mycelium...............................Stirps Tenax
2. Not as above.................................... 3
3. Pileus appearing glabrous, the cuticle a rather well-defined epithelium of
inflated cells; stipe ornamentation (if present) not darkening with aging................................. see Sect. Pseudoleccinum
3. Not as above....................................... 4
4. Spores 8-11 x 3-5 z........................ Stirps Roxanae
4. Spores typically 10 / or more long....................... 5
5. Pileus trichodermium containing elements having some short cells which
are inflated, at times many of them................. Stirps Illudens
5. Pileus trichodermium of hyphae with essentially tubular cells............................. (see Stirps Subtomentosus also) Stirps Subpalustris
Stirps AFFINIS
118. Boletus affinis Peck
Ann. Rept. N. Y. State Mus. 25:81. 1873
Suillus affinis (Peck) Kuntze, Rev. Gen. PI. 3(2):535. 1898.
Ceriomyces affinis (Peck) Murrill, Mycologia 1:149. 1909.
Xanthoconium affine (Peck) Singer, Amer. Midl. Nat. 37:88. 1947.
Var. affinis
Illus. Pls. 97, 101 (above).
Pileus 5-10 cm broad, convex to broadly convex; surface dry and
decidedly rugulose overall at first, irregularities not so pronounced in
age, vinaceous-brown ("pecan-brown") overall at first, gradually changing to "clay color" or "cinnamon-buff" (pale dingy tan), surface micaceous under a lens, margin fertile. Context firm, white, unchanging, taste
mild to faintly disagreeable, odor not distinctive, with FeSO4 - lowly
olive-gray; NH4OH on cuticle rusty tan.
Tubes 10-12 mm long, becoming depressed around the stipe, white
at first, becoming "cinnamon-buff' or a stronger yellowish tan; pores
round, 1-2 per mm, staining yellowish slightly when injured.