ON CHENOPODIACE.E 113 



25. Uromyces Betae Lev. 



Uredo Betae Pers. Syn. p. 220. 



Trichobasis Betae Cooke, Handb. p. 530 ; Micr. Fung. p. 225. 



Uromyces Betae Lev. Ann. Sci. Nat. ser. 3, viii. 375. Cooke, Micr. 

 Fung. p. 213. Plowr. Ured. p. 127. Sacc. Syll. vii. 536. Sydow, 

 Monogr. ii. 224. Fischer, Ured. Schweiz, p. 10, f. 9. McAlpine, 

 Rusts of Australia, p. 100, f. 148—9, 316, and pi. H. 



Nigredo Betae Arthur, N. Amer. Fl. vii. 245. 



Spermogones. In little clusters, honey-coloured. 



JEcidiospores. yEcidia amphigenous, often on rounded or 

 irregular yellowish spots, collected into rather large clusters 

 which are round or sometimes irregular and confluent, cup- 

 shaped, yellowish, with a reflexed incised margin ; spores 

 delicately verruculose, pale-yellowish, 16 — 24 x 16 — 20 fi. 



Uredospores. Sori amphigenous, scattered, sometimes con- 

 centrically arranged, thick, pulvinate, 

 circular, up to 2 mm. diam., covered by 

 the epidermis which at length splits, 

 then pulverulent, cinnamon ; spores 

 globose to obovate-oblong, sparsely and 

 minutely echinulate, yellowish, 21 — 32 x Fig. 65. U. Betae. Te- 

 16— 26/x; epispore 24— S a thick, with i e ^ p °* e R and T d °" 



r" ' r r i r~ spore, on B. man tuna. 



two equatorial germ-pores. 



Teleutospores. Sori similar, but somewhat compact, dark- 

 brown ; spores globose to obovate, rounded and slightly thick- 

 ened above, with a minute hyaline hemispherical papilla, 

 smooth, pale-brown, 22 — 34 x 18 — 25 /x ; pedicels short, hyaline. 



On leaves of Beta maritima, B. vulgaris ; also doing great 

 harm to cultivated mangels. ^Ecidia rather rare, April — June ; 

 uredo- and teleutospores, rather common, May — October. 

 (Fig. 65.) 



In May all four spore-forms can sometimes be seen on the same leaf. 

 Kiihn says that the mycelium of the secidia is perennial, and that its 

 spores can reproduce the eecidia. If possible, the first leaves seen bearing 

 the eecidia should be collected and burnt ; this will check the disease at 

 the outset. If this is not possible, the plants may be sprayed with dilute 

 Bordeaux mixture or with potassium sulphide solution. Since in mangels 

 the disease would chiefly be reproduced by teleutospores from old leaves. 



G. u. 8 



