MYCOLOGIA 



Vol. XIV JANUARY, 1922 ' No. 1 



DIAGNOSES OF AMERICAN PORIAS— I* 



l. 0. overholts 

 (With Plate i and Figures 1-6 in the Text) 



Poria ambigua Bres., Atti Accad. Rovereto III 3: 84. 1897 



Original Description: Latissime efTusa, margine superiore re- 

 flexo, alba, demum stramineo-isabellina, subiculo membranaceo, 

 arete adnata, albo, tubuli ut plurimum obliqui, hie inde noduloso- 

 congesti, usque ad 8 mm. longi; pori majusculi, angulati, demum 

 dentato-laceri ; sporae hyalinae, obovatae, 5-8x3.5/*; basidia cla- 

 vata, 18-20 x 6-8 /x; cystidia fusoidea, apice muricelata et demum 

 laeva, 24-30x6-8^; hyphae subhymeniales tenuiter tunicatae, 

 septatae, 3-4 /x latae. 



Ad truncos Fagi, Carpini, . . . Piri communis . . . Robiniae 

 pseudacaciae. 



Nutat inter Poria et Irpices. 



Redescription: Annual, effused in orbicular or elongated patches 

 3-10 cm. long and 2-5 cm. broad, inseparable, where best devel- 

 oped with a regular, white, sterile, shortly pubescent margin 2-2.5 

 mm. broad ; subiculum thin, white, inconspicuous ; tubes unstrati- 

 fied, 0.5-6 (usually 2-4) mm. long, pure white to dirty white when 

 fresh, often cinnamon-buff to cinnamon in dried plants, angular, 

 very thin-walled, often with the shape of an inverted cone, the dis- 

 sepiments finely ciliate-dentate, averaging 1-3 per mm. ; spores 

 ellipsoidal or oblong-ellipsoidal, smooth, hyaline, 4-6x2.5-3.5^; 

 cystidia absent or very inconspicuous; tramal tissue compact, of 

 long and flexuous, simple or somewhat branched hyphae, with 

 occasional or rare cross walls, no clamps, diameter 3-4.5 /*; subicu- 

 lum hyphae more branched, with more numerous cross walls, no 

 clamps, diameter up to 6 /jl. 



* Contribution from the Department of Botany, The PearfsN^^Va^tate ^'ty, 

 College, No. 35. 



[Mycologia for November (13: 279-365) was issued 11 



i I* WAR 0 1922 



