[Vor. 1 
118 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
49. P. radiatus Sow. ex Fries, Syst. Myc. т: 369. 1821. 
Boletus radiatus Sow. Eng. Fungi pl. 196. 1799. 
Plants annual, sessile or decurrent; pileus dimidiate or flabel- 
liform and attached by an attenuate base, 2-5 x 2-7 x 0.3-2 
cm., firm and rigid, yellowish brown or rust-colored, velvety 
to glabrous, sometimes conspicuously zonate, sometimes azonate, 
margin thin or thick, acute; context yellowish to rusty brown, 
corky and somewhat friable, 2-5 mm. thick; tubes 1-8 mm. 
long, the mouths grayish umber to rusty red, circular, then 
angular, averaging 4-5 to a mm.; spores (teste Bresadola) 
yellowish, elliptical, 3.5—4.5 х 5.5-6.5 и. 
Growing commonly on Betula and Alnus. Rare. 
A species intermediate between P. gilvus Schw. ex Fries, 
and P. cuticularis Bull. ex Fries, distinguished from the former 
by the habitat, the brighter color and the smoother surface 
of the pileus, and by the colored spores, and from the latter 
chiefly in the habitat. Тһе species was reported from Ohio by 
Lea but I have not examined the plants. 
50. P. cuticularis Bull. ex Fries, Syst. Myc. 1:363. 1821. 
Boletus cuticularis Bull. Herb. Fr. pl. 462. 1809. 
Plants annual, sessile, often imbricate; pileus dimidiate or 
flabelliform and attached by an attenuate base, 3-7 x 3.5-10 
X 0.3-1 em., spongy and fleshy-tough when fresh, leathery to 
rigid when dry, yellowish brown to rusty brown, compact 
wooly-tomentose, becoming fibrillose or almost glabrous, some- 
times subzonate on the margin, margin thin, acute, often 
inflexed; context yellowish brown or rust-colored, tough and 
watery when fresh, distinctly fibrous, 2-7 mm. thick; tubes 
2-7 mm. long, the mouths hoary brown to rust-colored, angular, 
averaging 3-5 to а mm.; spores yellowish brown, smooth, 
subglobose to broadly elliptical, 4.2—5.7 x 5.5-7 и. 
On dead wood of deciduous trees. August to November. 
Common. 
This species is very closely related to P. radiatus Sow. ex 
Fries, but Ohio plants may be distinguished from that species 
_ by the habitat, the thicker and larger pileus, and by the more 
tomentose and spongy surface. Р. perplexus Peck, the types 
of which have been destroyed, is thought by some to be this 
species and our plants are frequently referred to it. 
