156 Bulletin 313 



oblong to chiefly subspherical or polyhedral, thick-walled (wall often 

 irregular thickened and lighter-colored where spores have been in 

 contact), verruculose, chiefly 12-19 fi in length." North American 

 Flora, V. 7, p. 39 (1906). 



902. Infected inflorescence of A. virginicus. 903. Spore balls, 2/3. 904. 

 Spores, 1/12. 



SoROSPORiUM SYNTHERisM^ (Peck.) Farl. — On the inflorescence 

 of Panicum proliferum. "Sori involving the entire inflorescence 

 elongate, 3-7 cm. in length, or rarely limited to individual spikelets 

 and then shorter, protected by leaf sheaths, provided with false mem- 

 brane that ruptures from the apex down disclosing black-brown 

 spore mass and shredded filaments of plant tissue; sterile cells of 

 membrane hyaline, oblong to circular or subspherical, with tendency 

 to adliere in filaments when separated, spore balls rather evanescent, 

 variable' in shape and size, irregularly oblong to spherical, 40-100 [i 

 in length, spores very minutely verruculose, inner often appearing 

 smooth, subspherical or somewhat polyhedral to occasionally more 

 elongate, chiefly 9-13 [x in length." North American Flora, v. 7, p. 38 

 (1906). 



90S. Infected inflorescence of P. Proliferum. 906 Spores, 1/12. 



TiLLETiA FCETENs (B. & C.) Trcl. — In the ovaries of wheat. "Sori 

 in ovaries, ovate tO' oblong, 5-8 mm. in length more or less concealed 

 by the glumes, all or only part of the ovaries of a spike infected ; 

 spores light to dark-brown, oblong to chiefly subspherical, occasion- 

 ally somewhat angular, foetid especially when young, smooth, chiefly 

 16-22 IX, the most elongate rarely 28 jx, in length." North American 

 Flora, V. 7, p. 48 (1906). 



907. Infected head of wheat. 908. Spores, 1/12. 



TiLLETiA TRiTici (Bjerk.) Wint— In the ovaries of wheat. "Sori 

 in ovaries, ovate to oblong, 5-8 mm. in length more or less concealed 

 by the glumes, sterile cells few, hyaline, subspherical with medium 

 thin wall, smaller than spores ; spores chiefly subspherical or spheri- 

 cal, light to dark-brown, with winged reticulations about 1 fx high b)' 

 2-4 IX wide, 16-22 fx in diameter." North American Flora, v. 7, p. 48 

 (1906). 



909. Spores, 1/12. 910. Larger spores from anothei- specimen, 1/12. 



