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Witson: NortH AMERICAN PERONOSPORALES 75 
description.” As the latter is too vague to allow of a more definite 
determination than would the mere citation of the host, this species 
had probably best be placed with the present one. The morph- 
ology of this species has been studied by Stevens.* 
On AMBROSIACEAE : 
Ambrosia artemisiaefolia L., Alabama, * Carver r8o ,; Illinois, 
“Hart; Kansas, *Swingle 1667 ; Massachusetts, */arlow 
(N. Am. Fungi 2056), *Seymour ; Missouri, *Demetrio (N. 
Am. Fungi 2427); New Jersey, *Halsted (Econ. Fungi 
291a), Stevens ; New York, Underwood ; South Dakota, 
Chaney, Williams (Econ. Fungi 2976); Wisconsin, Pam- 
mel, 
Ambrosia psilostachya DC., lowa, *Macbride ; South Dakota, 
Rydberg 798 ; Utah, Macbride. 
Ambrosia trifida L., Kansas, Swingle. 
Gaertneria a ee pa (Hook.) Britton, Utah, * Garrett (Fungi 
Columb. 2205). 
Tva ambrosiaefolia A. Gray, Arizona, * Griffiths (W. Am. Fungi 
336, on “ Franseria tenuifolia Gray 3 New Mexico, 7racy 
&Io. 
va ciliata Willd., Illinois, * art; Missouri, * Hart. 
On Carpuacear : 
Artemisia biennis Willd., Montana, Anderson & Kelsey. 
Carduus arvensis (L.) Robins., New York, Arthur, Brown, 
* Halsted (Econ. Fungi 302), Stevens, Underwood ; Ontario, 
Dearness, 
Carduus lanceolatus L., Newfoundland, ? Waghorne. 
Carduus muticus (Michx.) Pers., Minnesota, Holway 241 ; 
Ontario, Dearness. 
Carduus spinosissimus Walt., Louisiana, *Langlots 575 : : 
Matricaria matricarioides (Less.) Porter, California, Abrams 
2487; Oregon, *Lloyd. 
Parthenium integrifolium L., lowa, * Arthur. 
Parthenium repens Eggert, Kansas, Hitchcock 1086. 
? Senecio cymbalaroides Nutt., Montana, Kelsey. 
Senecio Hartianus Heller, Colorado, Rydberg & Vr eeland 5499- 
ee bee 
* Bot. Gaz. 32: 85, 07, 259. pf. 93 pl S- 43> 53- 497% 
