1915] 



OVERHOLTS — STUDIES IN THE POLYPORACEAE 707 



odor when fresh, soft and friable when dry, 2-7 mm. thick; 

 tubes 1.5-3 mm. long, the mouths white or yellowish, averag- 

 ing 3-4 to a mm. ; spores cylindric or allantoid, minute, hya- 

 line, 3-4 X 0.7-1.5 n; cystidia none; hyphae of context hya- 

 line, much branched. 



On dead wood of deciduous trees. 



Specimens examined: Mo. Bot. Herb. 4311 (Missouri). 

 Burt Herb, (collections from Vermont and New York). — 

 Overholts Herb. 2325, 2261, 2277, 2276 (New York), 2326 

 (Ohio). 



2. Polyporus albellus Peck. 



Plate 23, fig. 5, Plate 24, fig. 16a. 



Pileus soft and watery when fresh, rigid when dry, more or 

 less triangular in section, 1-8 X 1-7 X 1-4 cm., white or yel- 

 lowish, glabrous or nearly so, covered with a thin yellowish 

 pellicle that is more evident in dried plants, but often disap- 

 pears in patches; context white, soft and friable when dry, 

 0.5-3 cm. thick; tubes 4-9 mm. long, the mouths white or yel- 

 lowish, averaging 3-4 to a mm. ; spores cylindric or allantoid, 

 minute, hyaline, 3-4 X 0.7-1.5 n ; cystidia none ; hyphae of 

 context hyaline, unbranched or nearly so. 



On dead wood of deciduous trees. 



Specimens examined: Mo. Bot. Gard. Herb. 43756 (Idaho). 



Burt Herb, (collection from Pennsylvania). — Overholts 

 Herb. 591 (Vermont), 408, 149, 207 (Ohio), 2243, 2270 (New 

 York), 440 (Missouri). 



3. Polyporus spumeus Sow. ex Hornemann. 



Plate 24, figs. 10, 11, 14a. 



Pileus soft and watery when fresh, rigid on drying, 5-20 X 

 6-20 X 2-6 cm. (much thinner when dried), white or some- 

 what yellowish, villous-strigose or matted strigose-tomentose; 

 context white, rigid on drying, 1-3 cm. thick; tubes 0.5-1.5 cm. 

 long, collapsing when dried, the mouths white or yellowish, 

 averaging 2-4 to a mm.; spores ellipsoid to subglobose, hya- 

 line, smooth, often once guttulate, 5-6 X 4-5 n ; cystidia none. 



Illustrations: Hornemann, in Fl. Dan. pi. 1794. — Berk. 

 Outl. Brit. Fung. pi. 16, f. 4. 



