REED: SPECIALIZATION OF PARASITIC FUNGI 363 
same lack of specialization to particular hosts as Carleton reports for 
the crown rust in the United States. 
Puccinia glumarum (Schm.) Eriks. and Henn. Eriksson (34) is 
the only investigator to report on the host relations of this rust. He 
claims the existence of five specialized races: 
Tritict on Triticum vulgare. 
Secalis on Secale cereale and Triticum vulgare. 
Elymi on Elymus arenarius. 
Agropyri on Agropyron repens. 
Hordei on Hordeum vulgare. 
Puccinia dispersa Eriks. and Henn. Ericksson (34, 40) first 
separated the hosts of this rust into five distinct groups each sup- 
porting a distinct specialized race. Later each race was raised to 
specific rank, based on the host relations and life history. 
1. Secalis on Secale cereale. This race has its aecidial stage on different 
species of Anchusa. 
2. Agropyrti on Agropyron repens (Puccinia agropyrina Eriks.). 
Aecidial host unknown. 
3. Bromi on Bromus species (Puccinia bromina Eriks.). According to 
Miiller (99), this race has its aecidial stage on Pulmonaria mon- 
tana and Symphytum officinalis. 
4. Tritict on Triticum vulgare (Puccinia triticina Eriks.). Aecidial 
host unknown. 
5. Holci on Holcus lanatus and H. mollis (Puccinia holcina Eriks.). 
Aecidial host unknown. 
6. Triseti on Trisetum flavescens (Puccinia Triseti Eriks.). Aecidial 
host unknown. 
Miiller, Ward, and Freeman have studied the rust of the bromes. 
Miiller (103) found that aecidiospores from Pulmonaria montana 
infected Bromus arvensis, B. brachystachys, B. erectus, B. mollis and 
B. secalinus. Aecidiospores from Symphytum officinalis also infected 
these species of Bromus and, in addition, B. brizaeformis. Miiller 
obtained the following results with uredospores: (1) uredospores from 
Bromus erectus infected B. arvensis, B. brachystachys, B. erectus, B. 
macrostachys and B. mollis; (2) uredospores from B. arvensis infected 
B. arvensis, B. brachystachys, B. inermis and B. mollis; (3) uredospores 
from B. mollis infected B. brachystachys, B. macrostachys and B. mollis. 
Ward (171, 172) has carried out a large series of experiments with 
this rust. In his inoculation tests he used species of Bromus belonging 
to each of the five recognized subdivisions of the genus. Uredospores 
from eleven different species, belonging to three different sections of 
the genus, were used. Ward found marked differences in the sus- 
ceptibility of the bromes to the uredospores from different hosts. In 
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