UREDINEAE. 333 



The european Uredineae comprise the following families and 

 genera : I'uccinieae ( Uromyccs and Puccinia) ; Phragmidieae 

 (Tri2}hraf/mmm and Fliragmidium) ; Melampsoreae {Mclamysora , 

 Melampsoi'clla, Calyptospora, Coleosporium, Chrysomyxa, and Cron- 

 artium) ; Grjmnosporangieae {Gymnosporaiifjium) ; Endophylleae 

 {Endophyllum) ; also the genus Uredinojjsis on Ferns. 



Uromyces. 



Teleutospores unicellular and produced in flattened sori. 

 Only one teleutospore is abjointed from each sporophore. 

 Teleutospores with a single germ-pore. Uredospores, aecidia, 

 and pycnidia are not present in every species. 



(1) All forms of spore iJrescnt on the same liost-plmit : 



Uromyces ervi (Wallr.) (Britain).^ Vetch-rust. The aecidia 

 are produced on Vieia liirsuta in May and throughout the 

 sunnuer. Scattered amongst the aecidia are the sori from 

 which uredospores are sparingly given off in early summer ; 

 the teleutospores are given off abundantly from the same 

 sori from July onwards. The aecidiospores germinate on the 

 vetch plants, and produce therein a mycelium from which the 

 aecidia and teleutospores arise. Infection by means of sporidia, 

 derived from the teleutospores, results in the production of a 

 mycelium which bears aecidia only. Pycnidia (spermogoniu) 

 are absent in this species and also in U. fabac. 



U. fabae (Pers.), [U. orohi (Pers.)] (Britain and U.S. America). 

 This occurs on species of Vicia and Lathyrus. Sori are formed 

 abundantly and give off both uredospores and teleutospores — 

 the latter being smooth-coated. No pycnidia have as yet been 

 observed. 



U. trifolii (Hedw.). Clover-rust. Parasitic on various species 

 of clover. Uredo- and teleutospores are generally produced ; 

 aecidia have been found only on Trifolium rcpens (Germany and 

 Britain), T, incarnatum (Italy), T. pratense (Denmark, Britain, 

 and America). On Trifolium repiens both teleutospore and 

 aecidium generations cause swelling and distortion of leaf-ribs 

 and petioles, the deformation being most marked where the 

 mycelium has hibernated and produced teleutospores in spring. 



1 Tlie chief autliorities used for the occurrence of the Uredineae in Britain 

 and North America are Plowright (Britinh Ure.dineae, 1889), and Farlow and 

 Seymour (Host-Imlcx for U.S. America, 1891). (Edit.) 



