37° BOTANICAL GAZETTE : [APRIL 
development of uredinia in early spring from persistent mycelia of Puccinia 
glumarum on Secale cereale; P. coronata on Agrostis vulgaris and Agropyrum 
repens; P. Carduorum on Carduus crispus; Uredo Festucae on Festuca ovina; 
and probably also of Melampsora Lini on Linum catharticum, and P. bromina 
on Bromus mollis. 
In the neighborhood of Vienna, Hecke® finds that, as Ertksson and 
HENNING have occasionally observed in Sweden, Puccinia glumarum sometimes 
persists through the winter by means of hibernating mycelium in the leaves of 
wheat. In r1or4, rust pustules were observed in abundance on the old leaves 
in March, and from that time the rust was present continuously. No suc 
interruption of continuity between the spring outbreak and the summer out- 
break as was reported by Errksson was observed. An abundance of wintering 
mycelium the author regards as one of the conditions determining the occur- 
rence of rust epidemics or ‘rust years.”’ 
Brief notes on the wintering of the timothy rust, Puccinia Phleipratensis, 
have been published by Mercer’ and by HuncERFoRD.’ MERCER states 
that in North Dakota it is difficult to find uredospores of this rust after the 
first hard frost, and that the fungus is not active until late July. The new 
pustules are on new growths in all cases, and therefore do not arise from hiber- 
nating mycelia, by means of which Errksson and HENNING believe this rust 
lives through the winter in Sweden. Uredospores from rusted timothy straw 
exposed to the weather, but kept from moisture by means of open tin cylinders, 
did not germinate at any time from October to March. 
In Wisconsin, HUNGERFoRD finds that this rust behaves quite differently. 
Here uredospores capable of germinating were collected in the field in the 
months of October, November, December, January,-and March. On plants 
that were taken up in March, sori developed on the new growth and also on 
flecked places on the old leaves. The latter undoubtedly arose from a 
hibernating mycelium. 
Matns? reports the wintering of Coleosporium (in Michigan?) by means 
of hibernating mycelia. Uredospores capable of germination were collected 
in February and May. On ee brought in during January, new pustules 
developed on the old rosette leaves 
The fact that the position of spore pustules of rusts, whether on the uppeT 
or the lower surface of infected leaves, is usually included in the diagnosis of 
* Hecke, L., Zur Frage der Uberwinterung des Gelbrostes und das Zus are 
aera von Rostjahren. Naturw. Zeitschr. Forst.- u. Landwirtsch. 13:213-22 
915. 
7 Mercer, W. H. shes tant of timothy rust in North Dakota during 1913- 
Phytopath. 4: 20-22 
§ HUNGERFORD, W, Wintering of timothy rust in Wisconsin. Phytopath. 
42337-338. I9r4. 
9 MaIn 
6 Ans, F. B., The wintering of Coleosporium Solidaginis. Phytopath. 6:371- 
372. I91 
