Arthur: Cultures of Uredineae in 1910 



4 



May 10 on Carduus Flodmanii produced pycnia May 19 and aecia 

 June 5. Another collection from the same place but taken at a 

 different date was sown May 19 on Carduus Flodmanii, showing 

 pycnia May 28 and aecia June 5. Three other collections of what 

 appears to be the same rust on the same.host, also sent from Kulm, 

 N. Dak., by Dr. Brenckle but collected at different times were 

 sown on Carduus Flodmanii (various dates), and one of these 

 was also sown upon eighteen other species of hosts, all with no 

 infection. Still another collection on /. balticus from Granby, 

 Colo., sent by Mr. E. Bethel. was sown on Carduus Flodmanii 

 without infection. 



The results here given appear to support the suggestion made 

 in the last report 38 that this species is composed of races. The 

 failure to infect Pulicaria with American material, as there 

 stated, seems to indicate that American and European forms rep- 

 resent different races. The failure to infect Carduus with some 

 of the sowings was also doubtless due to the existence of races. 

 Mr. Bethel has since suggested that his collection from Granby is 

 probably connected with aecia on Arnica, and both Mr. Bethel 

 and Dr. Brenckle are of the opinion that there is a form of this 

 species with aecia on Ambrosia psilostachya. 



23. Uromyces Astragali Sacc, on Aragallus Lamberti 

 (Pursh) Greene (Oxytropis Lamberti Pursh), collected by Mr. 

 E. Bethel at Leyden, Colo., was sown on Euphorbia Cyparissias, 

 without result. 



A collection bearing uredinia (Uredo Oxytropi Peck) on Ara- 

 gallus Lamberti (Pursh) Greene, sent by Mr. Bethel from Boul- 

 der, Colo., was sown September 30, on Astragalus carolindanus, 

 giving rise to uredinia that were first noticed October 22. 



A collection bearing uredinia on Astragalus sulphurescens 

 Rydb., sent by Mr. E. Bethel, from Boulder, Colo., was sown 

 Sept. 30, on A. carolinianus, and on October 22, uredinia were 

 observed, although they may have appeared somewhat earlier. 



We have yet made no appreciable headway toward ascertaining 

 the aecial condition of this rust, but the present cultures do show 

 that the Oxytropis rust, which has usually been kept distinct, is 



m Mycologia 2: 220. 1910. 



