HYPOCREALES . 191 



Epichloe typh'ma forms cream-colored sheaths around the 

 stems of Phleum, Poa, Dactvlis, and other meadow grasses. 

 Enormous numbers of hyahne, ovate conidia cover the young 

 stromata. The perithecia are eventually seated within these 

 stromata, superseding the conidial or Ephelis stage. The peri- 

 thecial initials contain three- to five-celled ascogonia, each cell 

 being multinucleate. The protoplasts of a pair of these cells fuse; 

 ascogenous hyphae then form and eventually produce the asci. 

 The ascospores are hyaline and thread-like. 



Other closely related genera, occurring on grasses and having 

 similar conidial stages but purplish black stromata, are Balansia 

 and Dothichloe. Each also produces filamentous ascospores that 

 in Dothichloe separate into segments. The fertile stromata of 

 Balansia hy poxy Ion are cushion-shaped and sclerotium-like, and 

 they are elevated above the stroma that invests the grass stems. 

 Early studies of these genera within the United States were made 

 by Atkinson (1894, 1905) and more recent ones by Diehl (1930). 



The Genus Cordyceps was early monographed by Massee 

 (1895). It contains about 200 species, nearly all of which para- 

 sitize insects, transforming their tissues into sclerotia. The most 

 commonly encountered entomophthorous species are C. capitata 

 on scale insects and C. sphingiim and C. militaris on larvae and 

 pupae of various Lepidoptera. The remainder parasitize Elapho- 

 myces, especially E. cervimis and E. gramilatns. The develop- 

 ment and cytology of one of this second group, Cordyceps agar- 

 icijonnia, were studied by Jenkins (1934) and found to be quite 

 like those of Epichloe, Claviceps, and Polystigma. The stromata 

 of Cordyceps, or clavae, are stalked, and the perithecia are pro- 

 duced in the capitate tips. 



Shanor (1936), using as media living lepidopteran pupae placed 

 on sphagnum in moist chambers, grew Cordyceps jiiilitaris to 

 maturity. 



Claviceps purpurea and related species parasitize grasses, 

 especially the cereals, transforming the ovaries into sclerotia, 

 commonly called ergot grains. Monographic treatises by Atana- 

 soff (1920) and Barger (1931) summarize the numerous papers 

 dealing with this genus and with ergotism, the disease which re- 

 sults from ingestion of ergot grains or sclerotia. These sclerotia 

 are grayish violet externally and grayish white to white within. 

 Their size, which varies, is dependent upon that of the ovaries 



