DISEASES OF WIIJD PLANTS. 101 



The pycnidia are produced at the openings of the stomatal chim- 

 neys, and an aggregate of hyphoe generally closes the opening. 

 The spores are pale brown, straight or slightly curved, two to three 

 septate, and 25 to 30 by 3 /i. 



A species of Khabdospora may sometimes be associated with the 

 trouble, but it is apparently of secondary importance. 



Specimens collected : Austin : Falfurrias, 2467 : Itonnd Rock. 2407. 



PURSLANE. 



White-rust {Albugo portulacae (DC.) Kuntze). — This species of 

 white-rust has been found on two different species of Portulaca. 



Specimens collected: (1) On Portulaca oleracea L. — Beeville, 1811; Bastrop, 

 2028; Luling, 2248; Cuero, 25S5; Stockdale, 2632. (2) On Portulaca lanceolata 

 Eng.— Falfurrias, 2439. 



RAIN LILY. 



Rust {Pibcdnia cooperiae Long) . — On the leaves of the small rain 

 lily {Cooperia drummoTulii Herb.) are formed oval or elliptical 

 brown sori, often very abundantly aggregated. 



Specimen collected: Austin, 493. 



RIVINA. 



Leaf -spot {Cercospora flagellaris Ell. and Martin). — The general 

 symptomatology of this disease on Rivina laevis L. is the same as the 

 leaf -spot of the poke weed (p. 99). Since it also agrees in size of 

 conidiophores and conidia, it is very probably the same fungus, the 

 hosts being related. 



Specimens collected: Austin, 303, 1419. 



RUELLIA. 



Rust {Puccinia ruelliae (B. and Br.) Lagerh.). — On Ruellia tuhe- 

 rosa L. an abundance of sori are produced, punctiform to 1 mm. in 

 diameter, mostly upon the upper surface of the leaves. 



Specimens collected : Austin, 34, 412. 439 ; Beeville, 1797. 



SAGE. 



Rust {Puccinia farinacea Long). — Minute, rounded, brown sori 

 are formed on the upper surface of the leaves of sage {Salvia 

 farinacea L.). 



Specimen collected: Austin, 349. 



SENNA. 



Leaf -spot {Ramularia cassiaecola Heald and Wolf. Syn. — Cerco- 

 spora occidentalis Ell. and Kellerm.) — This fimgus on senna {Cassia 



226 



