2 73 CULTURES OF URED/NE/E IN i8gg [iqoo 



May 4, Teleutospores from A. furcatus sown on CEnothera biennis ; no 



infection. 

 May 15, yEcidiospores from P. pubescens sown on A. scoparius ; May 29, 



uredo. 



8. Puccini a angustata Pk. 

 The detection of the aecidium of this common rust on Scirpus 

 was also due to a fortunate observation. It was noticed that 

 some plants of Lycopus, growing within a few feet of Scirpus 

 atrovirens covered with last vear's teleutospores, were well 

 besprinkled with aecidia (Aicidium Lycopi Ger.), while plants 

 some distance away were free. Sowings of aecidia were made on 

 the leaves of the Scirpus and characteristic uredo obtained. The 

 hint was secured so late in the season that only one sowing was 

 possible, but the result is thought to be measurably reliable. 



May 23, vEcidiospores from Lycopus Americanus sown on Scirpus atrovirens ; 

 June 6, uredo. 



9. Puccima Windsors Schw. 



This rust occurs, often in great abundance, upon the much 

 benamed grass, Triodia cuprea (Sieglingia seslerioides Scrib.), 

 which in the days of Schweinitz was standing in the genus Wind- 

 soria. The name of the rust was applied in Burrill's Parasitic 

 Pungi of Illinois fourteen years ago, to the very different rust on 

 Muhlenbergia, hence great confusion has arisen, and in nearly all 

 recent lists and treatises the name is misused. 



The hint that led to successful cultures came from an obser- 

 vation upon proximity, as in the previous cases. A small shrub 

 of Ptelea trifoliata was made conspicuous by the bright yellow 

 spots of Aicidium Ptelece B. & C, and not ten feet away was a 

 large clump of the grass with the dead stems and leaves black 

 with teleutospores. Successful sowings of aecidiospores were 

 made on the grass, but the season by this time had advanced so 

 far that germinating teleutospores were no longer obtainable 

 with which to try the reverse cultures. The dates are as follows : 



May 15, Teleutospores sown on Ambrosia trifida ; no infection. 

 May 17, Teleutospores sown on Napcea dioica ; no infection. 

 June 8, y^cidiospores sown on Triodia cuprea ; June 15, uredo. 

 June 16, ^cidiospores sown on Triodia cuprea ; June 23, uredo. 



