[Vor. 1 
112 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
38. P. umbellatus Pers. ex Fries, Syst. Myc. 1:354. 1821. 
Boletus umbellatus Pers. Syn. Fung. 519. 1801. 
Plants stipitate, 7-20 cm. in diameter, the stipe branching 
repeatedly and giving rise to many centrally attached pileoli 
which are circular in outline, 1-4 ст. broad, less than 5 mm. 
thiek, fleshy in texture when fresh, rigid when dry, whitish 
to smoky brown in color, fibrillose or glabrous, azonate; mar- 
gin thin, acute, entire; context white, fleshy or fleshy-tough, 
rather brittle when dry, usually not more than 1 mm. thick; 
tubes less than 2 mm. long, decurrent on the stipe branches, the 
mouths white, angular, averaging 2-4 to a mm.; stipe compound, 
the branches cylindrical in form, central or subcentral, white, 
usually entirely covered with the decurrent tubes; spores 
white, oblong-elliptic, smooth, 2.3-3.5 x 7-9.4 y. 
Growing about the bases of stumps or trees, especially of 
Quercus. Rare. 
Easily distinguished from its allies by the more regular and 
cylindrical stipe branches, the small and centrally attached 
pilei which are more or less circular in outline, and by the ob- 
long-elliptic spores. Murrill describes it as Grifola ramosissima 
Scop. ex Murr. The plant is well illustrated by Lloyd (Syn. 
Stip. Polyp. f. 450), Hard (Mushrooms f. 320), and Atkinson 
(Mushrooms f. 183). 
39. P. frondosus Dicks. ex Fries, Syst. Myc. 1:355. 1821. 
Boletus frondosus Dickson, Fasc. Pl. Crypt. Brit. 1: 18. 1785. 
Plant stipitate, the stipe many times branching and giving 
rise to. numerous overlapping pileoli, the whole plant forming 
a more or less globose mass often as much as 40 cm. in diam- 
eter; pileoli flabelliform or spathulate in outline, 2-7 cm. broad, 
2-5 mm. thick, fleshy-tough when fresh, rigid when dry, grayish 
to mouse-colored, glabrous or minutely tomentose, azonate, the 
margin thin and acute; context white or whitish, fleshy-tough 
when fresh, fragile when dry, not more than 2 mm. thick; tubes 
2-3 mm. long, decurrent оп the stipe, the mouths white, angular 
or irregular, averaging 1-3 to a mm.; stipe compound, short 
and thick; spores white, smooth, ovoid to elliptical, 4.5-6 x 
6-9 u. 
Usually found at the bases of trees or stumps, preferably 
of Quercus and Ulmus. Common in late fall. 
