ON GRAMINEE 279 
30—45 x 16—22 4; pedicels short, brownish, persistent; an 
occasional mesospore is found. 
ns. 
N0 
Fig. 211. P. Poarum. Teleutospores ; a, uredospore on P. nemoralis; b, para- 
physes with same; c, mesospore; d, teleuto-sori on P. pratensis; e, typical 
teleuto-sori of Uromyces Poae, on the same. 
fEcidia on Tussilago Farfara, about May, June, and August, 
September, very common; uredo- and teleutospores on Poa 
annua, P. nemoralis, P. pratensis, P. trivialis, about July, 
August and October—December, common but easily overlooked 
unless searched for. (Fig. 211.) 
First stated by Nielsen, the connection of the two hosts was demon- 
strated by Plowright and Klebahn. This hetereecious Puccinia differs 
from all others in having two generations in one year. The earlier crop 
of wcidia begins to appear in May, and is followed by the uredo- and 
teleutospores on the surrounding leaves of Poa; these germinate quickly 
and the second crop of ecidia is produced about August, and the second 
generation of teleutospores may be found on Poa from October. The 
latter germinate in the following spring, but according to Lagerheim the 
uredospores algo, in a favourable climate, can survive the winter. This is 
certainly true in Australia, where (though the Puccinia is an introduced 
one) the uredospores have been found the whole year round. In that 
country the Coltsfoot does not exist, and the fungus is carried through 
the winter by the uredo-stage; in fact, according to McAlpine, it is most 
common in the winter there. Arthur and Carleton say that the fungus 
does the same as far north as Nebraska in North America, where the 
Coltsfoot is only a naturalised plant. Uredospores were found alive in 
every month of the year at Washington, D.C. 
In the Scottish Naturalist (’84, p. 270) this species is recorded for Poa 
Jluitans, but there may possibly be some error in this statement. Plow- 
right says that the uredospores are not accompanied by paraphyses, 
