SECTION OF VEGETABLE PATHOLOGY. 853 
fungus and carefully collect all leaves showing any sign of infec- 
tion and burn or otherwise destroy them. 
(d) TREATMENT. 
We are not aware that any direct mode of treatment has been suc- 
cessful in the case of fungi of the family Uredinee to which the Beet 
rust fungus belongs. If the annual infection is dependent upon 
the teleutospores we should seek to prevent, as far as possible, their 
formation. The only spores which are produced entirely independ- 
ent of the host are the sporidia, which are the product of the germi- 
nation of the teleutospores. ‘These sporidia are very delicate and 
exceedingly minute bodies, and if means can be devised for prevent- 
ing their coming upon the young beet plants, or, should this not be 
possible, a way discovered to prevent their germinating and entering 
the leaf tissues by the application of some fungicide (dilute solution 
of chloride of iron), the disease may be wholly, or in part prevented. 
(e) BIBLIOGRAPHY. 
Winter: Rabenhorst’s Kryptogamen | Kithn: Botanische Zeitung, 1869; 
Flora; 1; 1885; p. 155. Zeitschr. des Landw. Centralver. d: 
Sorauer: Pflanzenkrankheiten; Zweite Prov. Saschen, 1869; No. 2. 
Aufiage ; IL; p. 228. Persoon : Synopsis ; p. 220. 
A.D’Arbois de Jubainville et Julien | Strauss; (Uredocincta) Wetrerau Annal.; 
Vesque: Les Maladies des Plantes Cul- EE s* ps 96; 
tivées; p. 171. Vize, J. E.: Grev; V; 110. 
Frank: Die Krankheiten der Pflanzen; | Cooke, M.C.: Greville; VII; 187. 
II; p. 469. Halsted, B. D.: Bull. lowa Ag.Coll., 1888. 
5.—LEAar Rust OF THE CHERRY, PEACH, PLUM, ETC. 
Puccinia pruni-spinosee, Pers.* 
(Plate III.) 
(a) GENERAL OBSERVATIONS, DISTRIBUTION, ETC. 
The Leaf Rust here described is wide-spread in this country, having 
been observed in nine States, including Massachusetts, Florida, 
Louisiana, Texas, and California, a fact which would indicate a very 
general distribution. It is also known in Germany, France, and 
Great Britain. In the first-named country it is popularly called the 
‘*‘rust of the stone-fruit trees.” + 
With us it is most generally found upon the plum, but occurs 
also on the cherry, apricot, and peach. It has been described as the 
‘*plum tree brand.” 
The fungus producing the rust has been described under several 
different names; that used here is the one adopted by Winter. Some 
confusion has probably arisen from the fact that the uredo stage 
alone occurs upon the peach and from the resemblance of the uredo- 
spores to the teleutospores of Uromyces. 
The uredospores may or may not be present on the plum,t{ but on 
the specimens examined a few have been found in all cases mingled 
*The more important synonyms are Puccinia prunorum, Lk., Uredo prunastri, 
D. C., and Uromyces prunorum, Fekl. 
+ Frank, Die Krankheiten der Pflanzen, p. 486. 
¢ Peck, XXV, p. 119. 
AG 87 
su 
23 
