40 NORTH AMERICAN FLORA [Volume 7 



brown, usually opaque, ovoid to spherical, quite firm, composed of 6-20 or more spores, 

 chiefly 40-80 fi in length ; spores dark reddish-brown, ovoid to spherical or polyhedral, 

 smooth, about 12-17 fi in length. 



On Poaceae : 



Stipa comaia^ Wyoming. 



Shpa viridula, Colorado. 

 Type locality : Trinidad, Colorado, on Stipa vlridula. 

 Distribution : Colorado and Wyoming. 



9. Sorosporium Rhynchosporae P. Henn. Hedwigia 35 : 222. 1896. 



Sori in ovaries, completely concealed by the glumes, more or less subspherical , about 

 1 or 2 mm. in length, forming a granular black spore-mass; spore-balls dark-reddish to 

 black-brown, opaque, oblong to subspherical, more or less angular, rather firmly aggluti- 

 nated, usually of about 6-20 spores, 25^5 ^ in length ; spores dark reddish-brown, oblong to 

 spherical, with sides more or less angled, apparently smooth or obscurely verrucose, chiefly 

 10-16 II in length. 



On Cyperaceae : 



Rynchospora semiplumosa , Mississippi. 

 Type locality : Rio de Janeiro, Brazil, on Rynchospora glauca. 

 Distribution : Mississippi ; also in South America. 



Excluded species 



Sorosporium Borrichiae BlHs & Ev.; Millsp. Field Columb. Mus. Publ. Bot. 2: 16. 

 1900. On Borrichia argentea. = Sterigfnatocystis. 



8. THECAPHORA Fingerh. lyinnaea 10 : 230. 1835. 



Poikilosporium Dietel, Flora 83 : 87. 1897. 



Sori in various parts of the host, often as indefinite masses in the floral parts or form- 

 ing rather firm pustules on the stem, at maturity with a dusty spore-mass ; spore-balls 

 composed of fewto many fertile cells, rather permanently united, of small to medium large 

 size ; spores usually yellowish or reddish, smooth on contiguous sides but usually marked 

 on the free surface ; germination, so far as known, by means of a single sporidium at tip of 

 the elongate septate promycelium. 



Type, Thecaphora hyalina Fingerh. 



Sori pustular, 2-5 mm., on various parts of hosts. 



Spore-balls of 2-6 spores. 1. T. pilulaeformis. 



Spore-balls of 15-30 spores. 6. T. mexicana. 

 Spore-balls of 50 or more spores. 



' Host: Boerhaavia. 7. T. tunicata. 



Host : Cladolhrix. 8. T, Thornberi. 

 Sori indefinite, in the inflorescence. 

 Sori in the flower heads. 



Spore-balls of 2-6 spores. , 2. T. Trailii. 



Spore-balls of 7-20 spores. 3. T. californica. 



Spore-balls of 40-75 spores. ^ 4. T. cuneaia. 



Sori inside bracts of staminate spikes. 9. T. aterrima, 



Sori in the seeds. 5. T. deformans. 



1. Thecaphora pilulaeformis B. & C. Grevillea 3 : 58. 1874. 



Tolyposporium Davidsonii Dietel & Holway, Bot. Gaz. 19 : 305. 1894. (Type from California, on 



Isocoma veneta ; not on Airiplex^ as stated.) 

 Poikilosporium Davidsohnii Dietel, Flora 83 : 87. 1897. 



Poecilosporium Davidsohnii Sacc, & Sydow; Sacc. Syll. Fung. 16 : 380. 1902. 

 Sorosporium Bigeloviae Griff. Bull. Torrey Club 29 : 295. 1902. (Type from Arizona, on Bige- 



lovia sp.) 



Sori taking the place of the aborted inflorescence or often at the base of the leaves, 

 subspherical, small, forming firm usually clustered pustules, upon dehiscence disclosing 

 light-colored spore-mass ; spore-balls somewhat irregular, chiefly 2-6-spored, 14-25 // in 

 length ; spores yellowish, quite variable through pressure, oblong to polyhedral or often 

 three-sided in cross-section, with contiguous sides flattened and smooth but with the curved 

 free surface rather abundantly verruculose, chiefly 11-16 /^ in length. 



On Carduaceae : 



Isocoma veneta {Bigelovia veneta)^ California. 



Isocoma {Bigelovia) sp., Arizona. 

 Type locality : California, on Bigelovia veneta {Isocoma veneta). 



