CLAVICEPS. 195 



CI. nigricans (Tul.) on Hcleocharis and Scirpus, with sclcrotia 

 of a dark violet colour (Britain). 



CI. setuloso (Quel.) on Poa. Stromata straw-yellow in colour. 

 CI. pusilla Ces. on Andropogon Ischaemum. 



(2) SPHAERIACEAE. 



The group of the Sphaeriaceae includes eighteen families, 

 but only the following contain parasites of interest to us. 



Families : Trichosphaei^ieae, Melanomeae, A^nphisphaerieae, 

 Ciicuimtaruae, &plia&y^%deac, FUo^pdreae, Gnoinlmieac, Valsdic, 

 Diaipfpeae, and Alelailemiideac. 



TRICHOSPHAERIEAE 



(including Coleroa and Herpotrichia). 



Coleroa. 



The perithecia have thin walls with radiating bristles, and 

 sit superficially on the substratum. The asci have thickened 

 apices, and contain eight two-celled, faintly coloured spores. 



Coleroa chaetomium Kunze, occurs on living leaves of 

 Bid us cacsius and li. Idaeus. In addition to perithecia, it 

 forms conidia known as Exosporium ruhi Nees. 



C. alchemillae Grev. (Britain and U.S. America). On leaves 

 of Alclieinilld nilgaris. 



C. andromedae Rehm. On leaves of Andromeda ptolifolia. 



C. potentillae Fries (Britain and U.S. America). Leaves of 

 Potentdla atiscrina. It forms perithecia which are situated 

 on the leaf-ribs ; also conidia {Marsonia potentillae). 



C. subtilis Fuck. On leaves of Potentilla cinerea. 



C. circinans Fries. On leaves of Geranium rotundifolium and 

 G. vw/lr. 



C. petasitidis Fuck. On leaves of Prtasites officinalis. 



Trichosphaeria. 



Perithecia small, spherical or ovoid, and more or less hairy. 

 Paraphyses distinct. Spores with one, two, or four cells. 



We give this genus a wider scope than Winter, and include species with 

 one, two, and four-celled spores of hyaline or light colour, and whose 



