1926] 



BURT THELEPHORACEAE OF NORTH AMERICA. XV 307 



On bark of dead Salix lasiandra. Washington. November. 



The dried fructifications of A . helveolus have some resemblance 

 in aspect to those of Stereum rufum but swell on softening and 

 rise to a height of 2 mm. above the bark. The paraphyses were 

 described by Bresadola as "paraphysibus irregularibus, undulato- 

 restrictis, moniliformibus, laevibus, 3-6 [l crassis, apice interdum 

 subcapitals" but they do not show clearly in my preparation. 



Specimens examined : 

 Washington: Spokane, alt. 576 m., J. R. Weir, 16312, type (in 



Weir Herb.). 



A. macrodens Coker, Elisha Mitchell Scientif. Soc. Jour. 36: 

 155. pi. 15, upper jigs., pi. 31, f. 7-9. 1921. 



Type: part of type in Mo. Bot. Gard. Herb. 



" Forming irregular, often somewhat elongated patches about 

 2 mm. to 2 cm. long with well-defined margins and with much 

 the aspect of A. candidus; surface minutely pulverulent, pure 

 white, or pale cream when old and weathered; entire thickness 

 only about 150-190 \l, the structure in section much obscured by 

 very small crystals and the densely branched paraphyses. Ba- 

 sidia entirely embedded, 12-15 \l thick, irregular and bent, with 

 4 long, stout sterigmata, which only reach the surface by their 

 tips. Spores commonly rectangular in outline, the surface set 

 with a few large, irregularly placed, bluntly pointed spines which 

 are up to 4 pi long; body of spore 113^-15 X 18^-27 (i." 



On bark of living trees of Fraxinus and Salix. New Hampshire 

 to North Carolina. May to December. Probably common. 



" In passing the plant would be taken for A. candidus, but when 

 examined is seen to be much thinner with the closely pressed 

 margin not showing a dark underside. The spores are remark- 

 able and unlike any others in the genus." 



Specimens examined : 

 New Hampshire: Chocorua, W. G. Farlow, 1. 

 New York: Alcove, C. L. Shear, 1302, 1305; East Galway, E. A. 



Burt; Poughkeepsie, W. R. Gerard, 294, comm. by N. Y. Bot. 



Gard. Herb. 

 North Carolina: Chapel Hill, W. C. Coker, 4734, type, comm. by 



Univ. North Carolina Herb, (in Mo. Bot. Gard. Herb., 57427). 



