Arthur: New species of Uredineae 517 



/ 



Donovan 40jp. A leptopucciniaceous rust of 

 )pearance of Puccinia Xanthii. 



Melampsora albertensis sp. nov. 



II. Uredinia hypophyllous, numerous, scattered, round, 0.2-0.4 

 mm. across, early naked, pulverulent, pale-yellow, ruptured epi- 

 dermis noticeable ; paraphyses numerous, intermixed with the 

 spores, clavate, 9-15 by 67-90 /i, wall colorless, 3-5// thick, 

 smooth, stipe solid ; urediniospores flattened laterally, when seen 

 from the broad side broadly-elliptical, 16-19 by 25-27 /*, when 

 seen from the narrow side oblong, 13-15 by 23-27 [i f wall color- 

 less, 1.5-2/-/, much thickened on the flattened sides, 2.5-3.5/*, 

 evenly and sparsely verrucose-echinulate, without smooth 

 spots. 



III. Telia hypophyllous, numerous, small, irregular, often con- 

 fluent, usually crowded in more or less extensive groups about the 

 uredinia, subepidermal, waxy, orange-brown ; teliospores prismatic, 



o- 



i/i, 



thicker above, 2-3 /*, with an evident apical germpore. 



On Populus tremidoides Michx., Moraine Lake, Laggan, Alberta, 

 Canada, September, 1906, E. W. D. Holzvay. An interesting 

 species, being the second one on Populus recorded for America. 

 It differs from the common species in the smaller urediniospores 

 which have no smooth spot, and in having the teliospores slightly 

 thickened above. The gross appearance of the fungus is also 

 somewhat different. 



Uredo biocellata sp. nov. 



II. Uredinia amphigenous, scattered, round, large, 0.75-1.5 

 mm. across, subepidermal, without paraphyses or peridium, early 

 naked, pulverulent, light chocolate-brown, ruptured epidermis 

 noticeable; urediniospores broadly ellipsoid or obovate-globoid, 

 23-27 by 27-32//, wall light chestnut-brown, I.5-2/1 thick, 

 coarsely echinulate, depressed over the 2 opposite pores, but with 

 the cuticle greatly inflated, nearly colorless, smooth, forming 

 bullate areas 18-25 t l in diameter. 



On Pluchea purpurascens (L.) DC, Florida Keys, 1898, C. L. 

 Pollard 143. The inflated sides of the spores give them a con- 

 spicuously odd and distinctive appearance. 



