196 GRASSES OF IOWA. 



purpurea. Thus in Wisconsin I observed a large percentage of 

 timothy in an old pasture which contained many heads which 

 were ergotized. Blue grass {Poa protensls), Poa annua, Cala- 

 magrostis canadensis, Agrostis vulgaris, Glyceria fluitans, and 

 many others, in some seasons and localities, are diseased. 



OtJier forms of ergot. — It may be possible that some of the 

 forms of ergot on grass may be referred to other species. 

 Halsted states, however, that the ergot on Elyinus rohustus is 

 Claviceps purpurea. The Hordeum juhatum contained apparently 

 the same species, with some minor differences but these are due 

 to the nature of the host.* The Claviceps microcephala (Wallr) 

 Tul. occurs on Phragniites, G. set ulosa {Quel) Sicc with a yellow 

 stroma on Poa, and G. pusilla Ges o 3. Andropogon Ischaemum. 



Preventative measures. — With modern methods of cleaning 

 cereals there need be little fear of the presence of ergot in flour 

 but it still continues to be a decided menace to cattle, especially 

 where it develops in our grasses, as timothy, blue ■ grass, red 

 top, and wild rye. It is imperative to cut all of thes3 grasses 

 before the ergot is mature. The presence of ergot in these 

 wild grasses no doubt causes its spread to wheat and rye fields. 

 Von Thumen thinks that the Lolium perenne, so commonly culti- 

 vated in Europe, is largely responsible for its abundance in 

 Austria, f He emphasizes the importance of cutting the grass 

 in waste places several times during the year to prevent the 

 formation of ergot. 



CAT-TAIL FUNGUS. 



Cat- tail fungus, Epichloe typhina (Pers.) Tul. This fungus 

 was described by PersoonJ as Sphaeria typhina in 1801 and by 

 him recognized as parasitic. Tulasn8§ transferred it from the 

 genus Sphaeria to that of .Epichloe. It has been described 

 from an economic standpoint by several mycologists — Sorauer||, 

 De Baryl, Trelease**, Frankff and Tubeuf]:^. 



This fungus is occasionally very abundant and destructive 

 to timothy, and oscurs occasionally on other grasses, notably 



♦Bull. Dept. of Bot. Iowa Agrl. Ool. Amss. 1886: 19. 



*Bull. Dapt. ot Bot. Iowa Agrl. Ool. Ames. 1888: 8. 



tDle Bekampfung der Piizkrankheiten unserer Oulturgewaechse. 36. 



tSyn. method, fungorum. 29. 



§Selecta fungorum. 3: 24. 



llPflanzenkrankheiten. 410. 



H Flora 1863: 401 Bot. Zelt. 1865: 100. (According to Sorauer, 411 ». 



*»InBeal. Grasses of No. Am. 1: 423 (Ed. 1.) 



ttKrankheiten d. Pflanzen 458. /. 81 (Ed. 3.) 



*tPflanzenkrankheiten. 207. 



