430 Arthur and Kern : Peridermium 



20. Peridermium abietinum (A. & S.) Thuem. Mitth. 



Forstl. Vers. Oest. 2 : 320. 1880 

 Aecidium abietinum Alb. & Schw. Consp. Fung. Nisk. 120. 1805. 



» 



0. Pycnia amphigenous, numerous, inconspicuous, forming 

 imperfect rows on either leaf-surface, subepidermal, honey-yellow 

 becoming reddish-brown, globose, 100-150/2 broad, 100-130 /i 



high. • 



1. Aecia from a limited mycelium, hypophyllous in two rows 

 on yellow spots occupying part or all of a leaf, erumpent from slits 

 0.3—1.5 mm. long, low, 0.5 mm. or less high, dehiscent at apex ; 

 peridium colorless, delicate, lacerate, cells abutted, outer wall and 

 portions in contact much thickened, 5-7 a, transversely striate, 

 inner wall thin and smooth ; aeciospores ellipsoid, 15-22 by 20- 

 35 p, wall colorless, 2-3 fi thick, strongly and densely verrucose 

 with the exception of a smooth longitudinal stripe. 



On Pice a excelsa (Lam.) Link, in Europe, but not yet found in 



America. The peridial cells of this species, like those of Per. 



decoZorans, are abutted, and not overlapped as in related forms. 



The cells of the peridium, as well as the spores, are smaller than 



in Per. decoZorans, and the spores also have a smooth line, not 



found in Per. decolorans or other American forms. It is the aecial 



form of Chrysomyxa Lcdi (A. & S.) DeB. The teliai form has 



been collected in the White Mountains, New Hampshire, northern 



Wisconsin, and the Yellowstone Park, and consequently the aecial 



form should eventually be found in America. 



21. Peridermium pseudo-balsameum (D. & H.) nom. nov. 



Aecidium psauio-balsameitm D. & H. Erythea 7: 98. 1899. 



0. Pycnia hypophyllous, rather numerous, inconspicuous, 

 scattered, honey-yellow becoming blackish-brown, subepidermal, 

 globose, large, 160-175 [x broad. 



1. Aecia from a limited mycelium, hypophyllous, sparsely 

 arranged in two rows, on yellow spots occupying a part or all of 

 a leaf, deep-seated, cylindrical, 0.4-0.6 mm. in diam. by 0.75-1 

 mm. high, dehiscent at apex becoming deeply lacerate ; peridium 

 colorless, rather delicate, cells overlapping, walls not striate, inner 

 very coarsely verrucose, 5-7 fx thick including tubercles, outer 

 thinner, 3-4 ju; aeciospores broadly ellipsoid, 18-22 by 23-28 jx, 

 wall colorless, medium thick, 2.5-3.5 ft closely and rather finely 

 verrucose. 



On Abies grandis Lindl., Eureka, California, June 4, 1896, 



