DISEASES OF WILD AND CULTIVATED GRASSES. 53 



REED-GRASS. 



Leaf-spot {Hendersonia arundinacea (Desm.) Sacc). — This fungus 

 produces brown, elongated spots on the leaves of reed-grass {Phrag- 

 mites vulgaris (Lam.) B. S. P.). The spots are 1 to 2 cm. in length, 

 most commonly confluent, causing the drying of the leaves. The 

 upper surfaces of the affected areas at maturity become grayish with 

 a broAvn margin. 



Specimen collected : San Marcos, 2109. 



SAND BUR. 



Smut {Sorosporhnn syntherismae (Pk.) FarL). — This smut de- 

 stroys the complete inflorescence of the sand bur ( Cenchrus sp. ) . 



Specimen collected : Skidmore, 2807. 



SILVER BEARD-GRASS. 



Black-blotch {Phyllachora graminis (P.) Fckl.). — This parasite on 

 silver beard-grass {Andropogon argyraeus Schult.) produces on the 

 leaves black, shining blotches. The spots are small, oblong, prom- 

 inent, sometimes confluent, with a rugulose surface. The fructifica- 

 tion is not mature until the leaves are dead and decaying. 



Specimens collected: Austin, 297, 356. 



Smut {Tolyposporella brunki (Ell. and Gall.) Clint.). — The leaf 

 sheaths inclose a black, powdery mass of spores, which has taken the 

 place of the inflorescence. 



Specimen collected : Austin, 1727. 



SORGHUM. 



Bacterial blight {BacUlvs sorgld Burr.). — This trouble is very gen- 

 erally present on all the varieties of sorghum {Andropogon sorghum 

 (L.) Brot.) grown in this section, such as milo maize, Kafir corn, and 

 cane. It produces on the leaves elongated purplish or dark-brown 

 patches quite commonly confluent, so that large portions of the leaf 

 are discolored. Many of the specimens represent mixed infections 

 of Colletotrichum spots and bacterial blight. 



Specimens collected: Boerne, 1653; New Braunfels, 1691, 1701; Sabinal, 1968; 

 Hondo, 1993; Bastrop, 2020; Lockhart, 2067; Cotulla, 2161, 2203; Seguin, 2298; 

 Stockdale, 2612; Flatonia, 2723; Floresville, 2848. 



Head-smut {Sphacelotheca reiliana (Kuhn.) Clint.). — The head- 

 smut is not uncommon on the various varieties of sorghum, but is not 

 so generally abundant as the kernel smut. 



Specimens collected: San Antonio, 1794; Uvalde, 1926; Bastrop, 2051; San 

 Marcos, 2104; Seguin, 2292; Victoria, 2350; Stockdale, 2636; Gonzales, 2701; 

 Hallettsville, 2799. 



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