Uromyccs. 



, , Phragmopyxis, Diet. Teleutospore three-celled in a longitudinal 

 series, with outer layer swelling when moistened. Pig. 24 ^ 

 12 Phrazmidium* Link. Teleutospore three or more celled in a longi- 



O i _^11* ___ ___ 1-n-v *-*-*^-i r*4- r\-r\rf-\ 



tudinal series, 

 Fig. 25. 



and outer laver not swelling when moistened. 



'-I 



FIJ. 21. 



ri... -1-2. 



FIG. 23. 



FIG. 25. 



13. Sphaerophragmium, Magn. Teleutospore consisting of a spherical 

 head of four to nine cells, and arising from a single cell by longi- 

 tudinal and transverse fission. Fig. 26. 



Anthomyces, Diet. Teleutospores forming a head of ^ three to 

 eight cells, barne on a single stalk, and arising from a simple cell 

 by the formation of longitudinal septa. Several small sterile cells 

 at base. Fig. 27. 



Ravenelia, Berk. Teleutospores forming a more or less hemispheri- 

 cal, many-celled head, transversely and longitudinally septate, 

 arising from a stalk compounded of several hyphae, and with 

 several sterile cells or cvsts at the base. Fig. 28. 



FIG. 27. 



FIG. 28. 



Only four of these genera occur in Australia, and they will be dealt 

 with in the following order: Uromyces, Uromycladium, Puccinia, Phrag- 

 midium. 



UROMYCES Link. 



In this genus the teleutospores are unicellular as well as the uredospores, 

 and this has sometimes caused the one to be mistaken for the other, but the 

 single germ-pore in the former serves ito distinguish it. Besides, the uredo- 

 spores are always echinulate or warted, and while the teleutospores are 

 usually smooth, they may also be striated or warted, but the generally 

 greater thickening of the wall, and the fact that the contents are nearly 

 colourless, also serve to separate them. All the different spore-forms may 

 be present in the same host-plant, or they may be reduced to the teleutospore 

 alone. In clover rust (U . trifolii} and beet rust (U. betae) all the spore- 

 forms occur, but in the latter, although the rust is very common, I have 

 seldom found the aecidia, and Plowright states that the aecidia are very 

 rarely found even in Britain. 



Pea rust (Uromyccs pisi}, with its aecidia on Euphorbia and its uredo- 

 spores and teleutospores on the pea, has not been found here, nor any other 

 heteroecious species of this genus. 



