May 10,1924 
Puccinia graminis in the United States 
547 
Table VII.— Correlation table for 100 urediniospores of Puccinia graminis poae. 
Spore length , subject; spore width, relative. Coefficient of correlation = .038 
±.0673 
Spore Width 
13m 
14m 
15m 
16m 
17m 
18m 
15m 
1 
1 
17m 
2 
2 
9 
18 
4 
35 
19 m 
1 
4 
1 
25 
13 
2 
46 
• 
21m 
4 
4 
5 
4 
17 
23m 
1 
1 
3 
12 
14 
48 
21 
2 
109 
The varieties of P. graminis now known in the United States are as follows: 4 * 
P. graminis tritici Erikss. and Henn. (actually consists of many forms or races), 
P. graminis secalis Erikss. and Henn. (consists of several forms), P. graminis 
avenae Erikss. and Henn. (consists of several forms), P. graminis phleipratensis 
{Erikss. and Henn.) Stak. and Piem., P. graminis agrostis Erikss., and P. graminis 
poae Erikss. and Henn. The first three must be considered as group varieties, 
consisting of many forms which can be differentiated by their parasitic action 
on varieties of Triticum spp., Secale cereale, and Avena spp., respectively {12, 7, 
and 13). 
In addition to these the following have been described by Eriksson (3, p. 370- 
371) and by Jaczewski {5, p. 353) in Europe: P. graminis airae Erikss. and Henn., 
P. graminis calamagrostis Jacz. (P. graminis epigeii Erikss.), P. graminis aperae 
Jacz. and P. graminis arrhenatheri Jacz. [P. graminis avenae Erikss. and Henn., 
according to Eriksson {3, p. 370)]. 
It is not known how widely P. graminis poae is distributed in the United 
States. It has been found abundantly only near barberry bushes. The epi¬ 
demics on Poa compressa in 1922 and 1923 near Pontiac, Mich., clearly started 
from rusted barberries. Heavily rusted P. compressa also was found in 1923 near 
rusted barberry bushes in the vicinity of North Vernon, Ind. 6 
LITERATURE CITED 
(1) Carleton, M. A. 
1899. CEREAL RUSTS OF THE UNITED STATES: A PHYSIOLOGICAL INVESTI¬ 
GATION. U. S. Dept. Agr. Div. Veg. Phys. and Path. Bui. 16, 
74 p., illus. 
(2) Eriksson, J. 
1902. UEBER DIE SPEZIALISIERUNG DES GETREIDESCHWARZROSTES IN 
SCHWEDEN UND IN ANDEREN LANDERN. Centbl. Bakt. (II) 9: 
590-607, 654-658. 
(3) - 1918. FORTGESETZTE STUDIEN UBER DIE SPEZIALISIERUNG DES 
GETREIDE-SCHWARZROSTES (PUCCINIA GRAMINIS) IN SCHWEDEN 
und in anderen landern. Centbl. Bakt. (II) 48: 349-417. 
(4) - and Henning, E. 
1896. die getreideroste . . . 464 p., illus. Stockholm. 
4 For list of host plants see Stakman and Piemeisel 04). 
* Specimens and information furnished by F. J. Eliason and W. F. Graham, field assistants, Office o f 
Cereal Investigations, Bureau of Plant Industry, U. S. Department of Agriculture. 
