DISEASES OF TKEES AND SHRUBS. 77 



This is apparently the same species of Cercospora which we have 

 described as causing a leaf spot of crape myrtle (p. 64), a closely 

 related host, and the difference in the conidiophores is no more than 

 might be expected from growth upon different hosts. 



Specimens collected: Beeville, 1829; Falfurnas, 2472; Victoria, 2510, 2515; 

 Cuero, 2589; Flatonia, 2738. 



PRICKLY ASH. 



Rust {Aecidium xanthoxyli Pk.). — Cluster cups were found on 

 the leaves of prickly ash {Zanthoxylum clava-herculis L.) ; espe- 

 cially abundant in the vicinity of Austin. 



Specimens collected : Elgin, 1872 ; Austin, 3114. 



Sooty mold {Fwrhago vagamf P.). — This forms a sooty coating 

 on the foliage. 



Specimen collected : Austin, 419. 



PRIVET. 



Leaf-spot {Cercos'pora adusta Heald and Wolf, 32.) — This forms on 

 the privet {Ligustrum spp.) dark-brown areas involving large spots, 

 frequently extending from the tip downward or from the margin 

 inward. Rarely are the spots removed from the margin. The 

 older diseased parts become very dark and the newer, brown, with 

 a gradual shading out into the chlorotic tissue. Conidiophores 100 

 to 150 by 4 to 5 ;«,, brown and septate, appear on both surfaces in 

 small clusters. The conidia are densely granular, clear, multi- 

 septate, and 85 to 160 by 3 to 4 /x. (PI. Ill, fig. 1.) 



Alternaria is abundantly present on the spots, probably as a sap- 

 rophyte. 



Specimens collected: On Ligustrum ovalifoUum Hassk. — Falfurrias, 2471 

 (type specimen) ; Floresville, 2851. 



Leaf-spot {Cercospora Ugustri Roum.). — Somewhat circular or 

 irregular spots, sometimes as large as 7 mm., are formed. They are 

 brown with a grayish center above and brown below. The margin 

 is purplish or darker brown. (PI. XV, fig. 1.) 



Specimen collected : On Ligustrum japonicum Thunb. — Austin, 131(3. 



Leaf -spot {Phyllosticta ovalifoUi Brun.). — Small circular brown 

 spots 2 or 3 mm. in diameter, with a darker margin, occur on the 

 leaves. The black pycnidia are few in each area. 



Specimen collected : On Ligustrum ovalifoUum Hassk. — San Antonio, 1405. 



REDBUD. 



Leaf -spot {Cercospora cercidicola Ell.). — In the beginning small 

 brown spots appear on the leaves of the redbud {Cercis occidentalis 

 Torr.). These spots become 2 to 4 mm. in diameter, angular, dark 

 brown above and brown below, with a region of yellow tissue sur- 



226 



