78 A PLANT-DISEASE SURVEY IN TEXAS. 



rounding each spot. The leaves become badly spotted, and defolia- 

 tion results. 



Specimens collected: Kerrville, 1621; Austin, 1913; Georgetown, 2397. 



RETAMA. 



Sooty mold (Dimerosporium parkinsoniae Heald and Wolf, 32). — 

 The leaves and smaller twigs and even the smooth bark of larger 

 branches of retama (Parkinsonia aculeata L.) are sometimes covered 

 with patches made up of dense aggregates of brown, septate hyphse. 



The conidia are dark brown, one to four celled, and also muriform. 

 (PL VII, fig. 2.) The asci are eight spored, 45 to 50 by 12 to 15 p; 

 spores hyaline, two celled, lower cell smaller, both biguttulate, and 

 15 to 18 by 4 to 6 /*. (PL VII, fig. 1.) 



Specimens collected: Austin, 455; Seguin, 2311 (type specimen); Gonzales, 

 2658; Hallettsville, 2901. 



SUMAC. 



Leaf -spot ( Oercospora rhoina Cke. and Ell. ) . — Circular or irregular 

 brown or dark-brown, almost black, spots, 3 to 5 mm. in diameter, 

 are formed on the leaves of sumac (Rhus copallina lanceolata Gray). 

 They have a tendency to be marginal and extend inward, the outline 

 being angular, due to the veins of the leaf. 



Specimens collected: Austin, 218; Georgetown, 2399. 



SWAMP CYPRESS. 



Leaf -blight (Pestalozzia funerea Desm.). — In this disease the leaf- 

 lets of the swamp cypress (Taxodium distichum (L.) Rich.) turn 

 brown. Beginning at the tips, they become brown throughout, or 

 show somewhat grayish, with an abundance of black acervuli. The 

 foliage of affected trees was badly blighted. In one collection show- 

 ing similar symptoms the Pestalozzia was not present, but an Al- 

 ternaria species was found, so it may be possible that the Pestalozzia 

 is only a secondary factor in producing the disease. 



Specimens collected: Victoria, 2535; Gonzales, 2678. 



SYCAMORE. 



Blight (Gloeosporium nervisequum (Fckl.) Sacc). — This blight, 

 which is characterized by the formation of dead areas beginning at 

 the margin of the leaf or the tips of the lobes and spreading through- 

 out the leaf, is very destructive to the sycamore [Plat anus occiden- 

 talis L.) in the more humid portion of this territory, but rare in 

 the western and southwestern portion. 



Specimens collected: Tyler, 1550; New Braunfels, 1723; Bastrop, 2056; San 

 Marcos, 2118; Georgetown, 2371; Flatonia, 2710; Hallettsville, 2774; Falfur- 

 rias, 2470. 

 226 



