UREDINEAE. 333 



The european Uredineae comprise' the following families find 

 genera : Puccinieae ( Uromyces and Puccinia) ; Phragmidieae 

 (Triphragmmm and Phragmidium) ; Melampsoreae {Melampsora, 

 Melampsorella, Galyptospora, Coleosporium, Ghrysomyxa, and Gron- 

 artium) ; Gymnosporangieae (Gymnoqyorangium) ; Endophylleae 

 {Endophyllum) ; also the genus Uredinopsis 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 present on the same host-plant : 



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

 are produced on Vicia hirsuta in May and throughout the 

 summer. 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 (spermogonia) 

 are absent in this species and also in V. fabae. 



U. fabae (Pers.), \TJ. ordbi (Pers.)] (Britain and U.S. America). 

 This occurs on species of Vieia 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 repens (Germany and 

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

 and America). On Trifolium repens 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. 



iThe chief authorities used for the occurrence of the Uredineae in Britain 

 and North America are Plowright {British Uredineae, 1889), and Farlow and 

 Seymour (Hosl-Iiidex for U.S. America, 1891). (Edit.) 



