LITERATURE CITED 303 



Stromata small, perithecium-like, subepidermal, often eventually external. At 

 maturity only a single large cavity with a cluster of spreading asci, the 

 intervening stromatic tissues entirely destroyed or remaining as remnants 

 between the basal portions of the asci. Family Mycosphaerellaceae 



Mycosphaerella, Dichjmellina, Guignardia. 

 Similar to the foregoing but the asci mostly parallel with more pronounced 

 remnants of stromatic tissues between them. 



Family Pleosporaceae 

 Physalospora, Venturia, Pleospora, Leptosphaeria. 

 Stromata more pronounced, subcortical or subepidermal. Walls surrounding the 

 large central perithecial cavities thick. 

 Outer stromatal wall with thick blackened external layer. Asci broadly clavate. 

 The pseudoperithecia single or scattered. Family Botryosphaeriaceae 



Botryosphaeria. 

 Outer wall with thin blackened layer. Asci elongated, nearly cylindrical. Pseudo- 

 perithecia densely clustered on the small or large basal portion of the 

 stroma. Family Cucurbitariaceae 



Cucurbitaria. 



Key to the Families of Order Hemisphaeriales 



{This follows Theissen and Sydow, 1917, and probably needs radical rearrangement) 



Ascocarps with more or less pronounced radial structure. 



Ascocarps arising subcuticularly but emerging, at least at maturity. Vegetative 

 mycelium scanty or lacking. Family Stigmateaceae 



Stigmatea. 

 Ascocarps produced externally on strands of hyphae from the internal my- 

 celium ("hypostroma"). Family Polystomellaceae 

 Polystomella, Parniularia (Schneepia). 

 Vegetative mycelium and ascocarps entirely superficial. Ascocarps round or 

 laterally compressed. Family Microthyriaceae 

 Microthyriuni, Asterina, Lembosia. 

 Mycelium conspicuous, external, radial or forming parallel ribbons of closely 

 united hyphae. Cover of the ascocarp arises as a thickening of the vege- 

 tative mycelium and is radial at least toward the margin. 



Family Trichopeltaceae 

 Trichopeltis. 

 Ascocarps not showing radial structure. Mycelium reticulate and superficial or 

 almost lacking. Family Hemisphaeriaceae 



Micropeltis. 



Literature Cited 



Ames, L. M. : An hermaphroditic self-sterile but cross-fertile condition in Pleurage 



anserina, Bull. Torrey Botan. Club, 59(6):341-345. Fig. 1. 1932. 

 : Hermaphroditism involving self-sterility and cross-fertility in the Asco- 



mycete Pleurage anserina, Mycologia, 26(5) :392-414. Figs. 1-6. 1934. 

 Arnaud, G.: Les Asterin^es: IV. Etudes sur la systematique des champignons 



pyrenomycetes, Ann. sci. nat. Botan., Xme s^r., 7:643-723. Pis. 1-16. Figs 



1-25. 1925. 

 — ■: Les Asterinees: V. Etude sur les champignons parasites: Caliciac^es, 



Hemispheriac^es, etc., A7in. epiphyt., 16:235-302. Pis. 1-14. Figs. 1-15 



1930. 



