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

BOLETELL US

387

yellowish especially near the trichodermium. Surface of stipe a layer of
incrusted interwoven hyphae yellow in KOH. Clamp connections absent.
Habit, habitat, and distribution.-Solitary to gregarious in oak
woods, especially around very old decaying logs and stumps, July and
August or early September, common at times during warm wet weather
in southern Michigan.
Observations.-The. spores serve quickly to distinguish this species
from the Boletus chrysenteron-fraternus complex.
Material examined.-Barry: Mazzer 8-19-66. Cheboygan: Shaffer
1587; Smith 37326, 37556, 63827, 7-23-52; Thiers 3613. Gratiot:
Potter 3380, 3804, 7852, 7854, 8154, 8177, 8231, 8386, 8424, 8444,
9830, 10051, 11780. 12663, 12842. 13393. Livingston: Hoseney 508;
Smith 7048, 18516, 18615, 64192, 64347. Oakland: Smith 6689, 6959,
7086, 7117, 18745, 73289. Roscommon: Potter 10158b. Washtenaw:
Hoseney 195, 543; Kauffman 8-13-15; Smith 1681, 15313, 62661,
64150; Thiers 4521.
209. Boletellus intermedius Smith & Thiers, sp. nov.
Illus. Fig. 114; P1. 154.
Pileus 4-10 cm latus, convexus demum late convexus, siccus, subtomentosus, roseus demum subolivaceus. Contextus luteus tactu
caeruleus. Tubuli 7-12 mm longi, laete lutei, tactu caerulei; pori lati (1
mm) lutei. Stipes 6-12 cm longus, 8-17 mm crassus, intus luteus tactu
caeruleus, extus rubro-pruinosus, non-reticulatus. Sporae 9-12 (13) X
4-5 g. Specimen typicum in Herb. Univ. Mich. conservatum est; prope
Pinckney, September 11, 1965, legit R. Homola (Smith 72559).
Pileus 4-10 cm broad, convex with a bent in margin, becoming
broadly convex to nearly plane; surface dry and subtomentose (plushlike), when young rose-red ("Pompeian-red") but soon duller from an
olive overcast and entire pileus usually olive-gray in age except for rose
to pink tints showing where cuticle is cracked, in age the pileus areolate.
Context yellow staining blue, taste mild, odor fungoid or lacking,
Melzer's on cuticle slowly olive, FeSO4 on context no reaction, KOH
yellowish to tan.
Tubes 7-12 mm long, depressed around the stipe, pale bright
yellow when young, greenish yellow in age, staining bluish when injured;
pores up to 1 mm wide, irregular in outline; breaking downward as in
Boletus.
Stipe 6-12 cm long, 8-17 mm thick at apex (rarely 3 cm in widest
dimension when compressed), solid, interior yellow staining blue, in base