270 MANUAL OF TREE DISEASES 



Leaf-Rust 



Caused by Gallowaya pini (Galloway) Arthur 



The leaves of scrub pine are commonly affected by this rust 

 throughout its range in central eastern United States. This 

 disease differs from the blister-rusts of pine needles in the 

 teliospores being borne on the pine and no alternate host being 

 required (see page 265). Yellow spots occur near the tips of 

 the leaves. On these spots are formed linear, reddish orange 

 pustules which burst through the epidermis. These pustules 

 may be a half inch long. The bright color soon fades and they 

 are inconspicuous. The teliospores germinate in the spring, 

 producing basidiospores which infect other scrub pine needles. 



Leaf-Cast of White Pine 



Caused by Hypoderma strobicola Tubeuf 



White pine is sometimes injiu-ed in eastern United States 

 by this leaf-cast. Pitch pine and hemlock are reported to be 

 affected by the same disease. The affected needles at first 

 show yellowish spots and later turn reddish yellow and brown. 

 The tissues of the twig may also be killed. Later in the season 

 several small elliptical black fruiting-bodies appear on the 

 outer surface of the needles. The fruiting-bodies are mature 

 the following spring. They split open and the spores are shot 

 into the air during prolonged rain periods. For further details 

 concerning the leaf-cast diseases, see page 38. 



References 



Graves, A. H. Leaf blight. Lophodermium brachysporum Rostrup. 



In Notes on diseases of trees in the southern Appalachians 1. 



Phytopathology 3 : 133-139, figs. 5-10. 1913. 

 Spaulding, P. The present status of the white-pine blights. U. S. 



Dept. Agr. Bur. PI. Ind. Circ. 35 : 1-12. 1909. 



