2IO British Uredinccs and Ustilazineo'. 



Biology. — The presence of the mycelium causes elongated fusi- 

 form swellings on the petioles and midribs. It differs from P. sene- 

 cionis in the darker colour of the sori, which are almost black. 



VI. LEPTOPUCCINIA. Schrot. 



Having teleutospores only, which germinate upon the living plant as soon 

 as they have arrived at maturity. The germ-tubes of the promycelial spores 

 enter the host-plant either through the stomata or between the epidermal cells. 



Puccinia arenarise. (Schum.) 



Teleutospores — Sori compact, pulvinate, roundish, scattered, often 

 circinate. Spores broadly fusiform or pyriform, summits 

 pointed or rounded, often thickened, base rounded or attenu- 

 ated, slightly constricted, smooth, pale yellowish brown, 30-50 

 X 10-20/X. Pedicels hyaline, colourless, as long as the 

 spores. 



Synonyms. 



Puccinia arenarice (Schum.). Winter in Rabh., " Krypt, Flor,," 

 vol, i. p. 169. 



Uredo arenarice.. Schum., " Enum. Plant. SselL," vol. ii. p. 232, 



Puccinia lychnidearum. Link. Berk., " Eng. Flor.," vol. v. 

 p. 367, in part. Cooke, "Hdbk.," p. 505, in part; "Micro. 

 Fungi," 4th edit., p. 210, in part. 



Puccinia i?icehringicB, Fckl. Cooke, " Micro. Fungi," 4th 

 edit., p. 210. 



Puccinia stellarice, Duby. Vize, Exs. 



Puccinia sagincn, Fckl. Vize, Exs. 



Puccinia dianthi, D. C. Vize, Exs. 



Puccinia spergulce, D. C. Cooke, "Micro. Fungi," 4th edit., 



p. 210. 



Exsiccati. 



Cooke, i. 8, 297; ii. 129, 130, 321, 432. Vize, "Micro. 

 Fungi," 35, 125; "Micro. Fungi Brit.," 32, 35. 



On Diajithus barbatus, Moehringia trinervia, Stellaria media, 

 uliginosa, holostea, Sagina fiodosa, prociimbens, Spergula arvensis. 

 May to November. 



Biology. — Cornu found that the teleutospores from M. trinervia 

 reproduced themselves in twenty-nine days on Alsine media and 



