K)2 



UROMYi ES 



On leaves of Phaseolus vulgaris. .May. .Inly — October: 

 even earlier on forced plants, Uncommon. (Fig. 55.) 



De Bary I.e. proved the genetic connection of the aecidia with the 

 uredo- and teleutospores. The aecidia are rarely met with; they may 

 occur either before or in company with the other spore-forms. 1 have 

 seen no proof that they have been found in this country. The description 

 i- founded upon that of Sydow. Fischer says that this species is rery 

 common in Switzerland on Phaseolus; it may become a dangerous pan 

 on forced Beans. All affected plants (leaves and stems should be burnt. 



/'. appendiculatus of Sydow, which oc.-m-s nany Leguminosie, is 



probably a collective species, though no experiments bearing on this point 

 are available. 



Distribution: as a collective species (U. appendiculatus) 

 world-wide. 



16. Uromyces tuberculatus Fckl. 



/Ecidiwm Eupkorbiae Gmel. in Linn. Syst. Nat. ii. 1473 p.p. Purton, 

 Midi. Flor. iii. 293. Cooke, Handb. p. 537 ; Micr. Fung. p. 195 p.p. 

 Plowr. Ured. p. 270. 



Uromyces excavatus DC; Cooke, Grevillea. ii. 161 ; Micr. Fung. p. 213. 



U. tuberculatus Fckl. Symb. Myc. p. 64. Sydow, Monogr. ii. 165. 

 Fischer, Ured. Schweiz, p. 43, f. 33. 



U. proeminens Lev. ; Sacc. Syll. vii. 553 p.p. 



Hypophyllous, spread uniformly over the 



Spermogones I 

 uEcidiospores 



whole leaf; secidia immersed, cup-shaped, with a short denticu- 

 late margin; spores orange, densely verruculose, 17 — 25 x 14 — 

 20 fi. 



Uredospores. Sori hypophyllous. scattered, at length naked, 



cinnamon ; spores more or less 

 globose, yellowish -brown, aculeo- 

 late,20 — 25/x: epispore 1^ — 2^/la 

 thick, with 5 — 7 swollen germ- 

 pores (4 — 5, Fischer). . 



Teleutospores. Sori amphi- 

 genous and on the stems, round, 

 scattered or sometimes arranged 

 in little groups, pulverulent, 

 blackish-brown or black: spores globose to ellipsoid, occasionally 



Fig. 56. U. tuberculatus. Two ma- 

 ture teleutospores ; a, a teleuto- 

 spore before the tubercles are 

 developed. 



