92 IKOMVCKS 



the leaves. The mycelium of the secidial stage is said to be perennial in 

 tin' host; Dietel says that in some Localities tin- secidiospores can re- 

 produce themselves, and that then the uredo is suppressed. 



Both this species and the preceding are distinguished from U. flectens 

 in the fad that tlu' sori are smaller, distributed more uniformly over the 



leaf, and do not ( ause distortions. 



The a M- id i i mi is ran- in I'.ritain (I have seen specimens only from Perth : 

 most of our records of I'romyces on T. repens belong to the following 

 common epecies, U. flectens. Pseudopeziza Trifolii (a Discomycete) is 

 common on leaves of white clover and is not infrequently mistaken for 

 the uredo-stage of U. Trifolii-repentis, bui is distinguishable by its being 

 confined to the upper surface of the leaves. No practical means of 

 prevention are known for either the Clover Rust {Uromyees) or the Clover 

 Leaf-spot {Pseudopeziza). 



DISTRIBUTION: Europe, Asia Minor, Persia, North and 

 South America, Australia. 



7. Uromyees flectens Lagerh. 



Uromyees flectens Lagerh. Svensk Bot. Tidskrift, iii. ."50. Sydow, 



Monogr. ii. 360. Grove, Journ. Bot. 1911, p. 366. 

 Puccinia neurophila De Toni, Sacc. Syll. vii. 698. 



Teieutospores. Sori hypophyllous, or more often on the 

 nerves and petioles where they cause swell- 

 ings and distortion, scattered, rather large, 

 ^ — 2 mm. long or even continent and larger, 

 long covered b}* the epidermis, then pul- 

 verulent, dark-brown ; spores as in U. 



Trifolii-repentis. 

 Fig. 44. U. flectens. 

 Teieutospores ou t. On Trifolium repens. May— October. 



Common. (Fig. 44.) 



repens, 



It has been frequently noticed that the Uromyees on Trifolium repens 

 behaves differently in different localities ; sometimes forming teieutospores 

 only, from .May to October; at others forming both secidia and uredospores 

 during the same time. Plowright records an interesting experiment which 

 he performed (Ured. p. 125) ; in October he brought a, plant of T. repens, 

 with the Uromyees upon it, indoors and kept it there till the following 

 summer. During all this time it produced only teieutospores. Lagerheim, 

 in 1909, noticing that the form which produced only teieutospores had 

 sori which were larger, more predominant upon nerves and petioles, and 

 remained longer covered by the epidermis, described this as a distinct 



