ON COMPOSIT 129 
This genus occupies an intermediate position between 
Uromyces and the less advanced genera, Phragmidium, etc., as 
is shown by the fact that many species tend to form one-celled 
teleutospores (mesospores) indistinguishable from those of 
Uromyces, while others have spores with three or more cells, 
arranged as in Phragmidium, Triphragmium, Sphaerophrag- 
mium, ete. 
The number of species is enormous, more than 1300 are 
already known. The genus must therefore be subdivided, but 
no quite satisfactory classification has as yet been discovered. 
Schréter’s and Fischer’s separate nearly allied species, while 
Arthur’s is a pathless chaos. As a temporary measure, instead 
of adding a new imperfect scheme to those already existing, 
the species are here arranged on the plan adopted in Sydows’ 
Monographia, in the order of the families and genera on which 
they are parasitic; this has the advantage that it does, to a 
great extent, bring nearly allied species 
close together, while it is at the same time 
very convenient for ccnsultation. In each 
family the genera are arranged in the order 
familiar to British botanists, but the fami- 
lies themselves are in the order usually: 
adopted on the continent, because that 
will before long be accepted here also. 
1. Puccinia Tripolii Wallr. 
Puceinia Tripoli Wallr. Fl. Crypt. Germ. ii. 
223. Cooke, Micr. Fung. p. 207; Gre- 
villea, iii. 180. 
P. Asteris Duby, Bot. Gall. ii. 888. Plowr. 
Grevillea, ii. 48; Ured. p. 215. Sace. 
Syll. vii. 687’ p.p. Sydow, Monogr. i. 
15 p.p. 
Teleutospores. Sori amphigenous, con- 
fluent into rather large, pulvinate masses, hard, compact, very 
dark-brown ; spores oblong-clavate or clavate, rounded above or 
somewhat narrowed and much thickened (as much as 8p), 
slightly constricted, generally attenuated downwards, smooth, 
Fig. 80. P. Tripolii. 
Teleutospores (one 
abnormal). 
G. U. 9 
