52 BROOKLYN BOTANIC GARDEN MEMOIRS 
Puccinia Pulsatillae Kalchbr. Bubak (22) distinguishes the fol- 
lowing races of this rust, basing the separation on the distribution and 
character of the sorus, not on cultural experiments: 
1. Concortica on Pulsatilla alpina and P. sulphurea. 
2. Atragenicola on Atragene alpina. 
3. Genuina on Anemone silvestris and Pulsatilla patens. 
. Pulsatillarum on Pulsatilla pratensis and P. vulgaris. 
Puccinia Ribis DC. Eriksson (39) distinguishes a specialized race 
Rubri, for he found that teleutospores from Ribes rubrum would infect 
this species but not R. nigrum nor R. Grossularia. 
Uromyces alchimillae (Pers.) Lév. Fischer (53) has carried out a 
few experiments with this rust which tend to show the existence of a 
host specialization. The results reported, however, do not indicate 
any close correspondence between the plants infected with a particular 
collection of uredospores and the systematic grouping of the host 
plants within the genus Alchimilla. Fischer found that uredospores 
from hosts belonging to the section Vulgares infected plants belonging 
to sections Pubescentes and Splendentes. 
Uromyces caryophyllinus (Schrank) Winter. Fischer (49-51) 
gives experimental evidence for the occurrence of specialized races in 
the carnation rust. The rust is heteroecious, the aecidial stage oc- 
curring on Euphorbia Gerardiana and the uredo and teleuto stages on 
various Caryophyllaceae. Fischer finds that aecidiospores from 
Euphorbia Gerardiana in one locality are able to infect only Tunica 
prolifera, while aecidiospores collected on the same host in another 
region are able to infect only Saponaria ocymoides. In still other 
localities, however, a race of rust is found that is able to infect both 
Tunica and Saponaria. 
Uromyces Dactylidis Otth and U.Poae Rabh. These rusts, 
probably indistinguishable by any well-defined structural character- 
istics, are further alike in having their aecidial stage on species of 
Ranunculus. The former develops its uredo and teleuto stages on 
Dactylis glomerata, while the latter has the corresponding stages on 
several species of Poa, Agrostis alba also being listed asa host. A large 
number of workers have contributed to our knowledge concerning the 
heteroecism of these rusts. 
Krieg (93, 94) and Klebahn (89, 91) have worked with Uromyces 
Dactylidis from the standpoint of specialization and the following 
races are indicated: 
1. Aecidial stage on Ranunculus bulbosus and R. repens. 
2. Aecidial stage on Ranunculus lanuginosus, to a slight extent on 
R. bulbosus (Uromyces lanuginosi-dactylidis Kleb.). 
3. Aecidial stage on Ranunculus aconitifolius, R. alpestris, R. glacialis, 
and R. platanifolius (Uromyces platanifolii-dactylidis Krieg.). 
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