DISEASES OF TREES AND SHRUBS. 65 



The conidiophores are densely clustered, 15 to 20 by 3 /n, continu- 

 ous, diluted brown in color, and are present on both surfaces, mostly 

 epiphyllous, however. The spores are 30 to 42 by 3 /*, 4 to 5 septate, 

 clavate or subcylindrical, and dilutedly colored. (PI. I, fig. 6. See 

 also "Pomegranate".) 



Specimen collected: Austin, 466 (type specimen). 



Leaf tip-blight. — This trouble begins as a drying of the leaf tips, 

 which become brownish in the dead portions. An extended zone of 

 chlorotic tissue gradually fading into the green marks the advancing 

 edge. The entire leaf may become dry and fall, exhibiting all the 

 appearances of a physiological trouble. Three fungi (Phyllosticta 

 lagerstroemia Ell. and Ev., Pestalozzia guepini Desm., and Cerco- 

 spora lythracearum Heald and Wolf) were present. 



Specimens collected : Beeville, 1857 ; Flatonia, 2748 ; Luling, 2254. 



DOGWOOD. 



Leaf-spot (Cercospora cornicola Tracy and Earle). — Very abun- 

 dant, indefinite-margined, irregular, brown spots are formed on the 

 foliage of the dogwood (Comics sp.). The margin is quite com- 

 monly purplish. The entire foliage becomes seriously affected. 



Specimens collected : Austin, 351 ; San Antonio, 1778 ; San Marcos, 2107 ; 

 Seguin, 2304 ; Victoria, 2534 ; Gonzales, 2706 ; Flatonia, 2749 ; Hallettsville, 2788, 

 2795. 



ELDERBERRY. 



Leaf -spot (Cercospora catenospora Atk.). — The spots on the leaves 

 of elderberry (Sambucus canadensis L.) caused by this fungus are 

 yellow at first, becoming gray with age. They are rounded or 

 elongated in the direction of venation and 3 to 6 mm. in greatest 

 length. They are often so numerous as to be confluent, resulting in 

 the chlorosis and subsequent fall of the foliage. 



Specimen collected: San Marcos, 2114. 



ELM. 



Blight. — The small-leaved elms (Ulmus spp.) frequently show a 

 blight or scald of the foliage which is characterized by the death 

 of the leaf tips. The dead, brown area advances downward until 

 the whole leaf may be involved. The brown area is generally bor- 

 dered by a zone of chlorotic tissue. In some cases the dead areas 

 are not terminal or marginal, but show as definite spots. This is 

 true for our specimens of Ulmus crassifolia. In some cases an 

 Alternaria is present, but it is not sufficiently constant to be defi- 

 nitely connected with the disease. 



Specimens collected: (1) On Ulmus alata Michx. — Gonzales, 2699; Kennedy, 

 2823. (2) On U. crassifolia Nutt— New Braunfels, 1719. 

 100833°— Bull. 226—12 5 



