]\IILDEWS, RUSTS AND SMUTS 
71 
conspicuous, and require to be carefully searched for. 
The teleutospore sori are remarkable in being emclosed in a 
peridium composed of more or less parallel, coloured h3^phae, 
a character that at once separates this from all allied genera. 
TRIPHRAGMIUM 
The peculiar structure of the teleutospores distinguish 
the present from every other British genus. They consist 
of three cells, but the three septa all radiate from the centre 
of the spore, thus each cell is triangular in outline, with 
the free or outside wall curved. 
One species grows on meadowsweet, the other on drop- 
wort. 
UROMYCES, Link. 
Pycnidia. Usually immersed, subglobose, with a slightly 
projecting conical neck. 
Aecidia. Peridia immersed, globose and closed at first, 
then open and cup-shaped. 
Uredospores. Sori pustulate or flattish. 
Teleutospores. Sori forming small dark-coloured pustules; 
spores one-celled, with a single germ-pore at the tip, ger¬ 
minating by the protrusion of a promycelium, which bears 
promycelium spores. 
Readily recognised by the i-celled teleutospores with a 
single germ-pore at the tip. 
According to Sydow there are 505 species of Uromyces 
known, their distribution is as follws : 
Species. 
Endemic. 
Europe ... 
. IIQ 
70 
Asia 
120 
73 
Africa 
. 78 
54 
Australia... 
. 31 
22 
America 
. 249 
VALERIANACEAE 
221 
Uromyees valerianae, Fuckel, Plowr., Ured., p. 128. 
Pycnidia. In minute groups, honey-colour. 
Aecidia. Usually on the under surface of the leaves, 
rarely on the stem or petioles, seated on thickened, pale 
spots, crowded or in irregular rings, edge recurved, torn, 
spores angularly-globose, orange, finely and densely warted, 
18^—25 p. 
Uredospores. On both surfaces of the leaf, generally on 
yellowish spots, scattered or clustered, minute, brown and 
