STEMONITIS 113 



2. Stemonitis (Gleditsc/i) Rest. 



1753. Stemonitis Gleditsch, in part, Meth. Fang., p. 140. 

 1873. Stemonitis (Gleditsch) Rost, Versuch, p. 7. 



Sporangia distinct, though often closely aggregate, cylin- 

 dric, stipitate ; columella prominent ; capillitium well developed 

 by repeated lateral and apical branching of the columella, at 

 length assuming at the surface the form of a distinct net which 

 supports an evanescent peridium. 



The genus is marked by its surface-net supported at the tips 

 of the dichotomously branched divisions of the columella. Over 

 the net is spread, theoretically at least, the peridial film sup- 

 ported by very short points projecting from the net, the perid- 

 ial processes; the peridium, however, is seldom seen ; in some 

 cases, certainly, is never developed. Rostafinski first defined 

 the genus as employed by recent writers. Gleditsch simply 

 renamed Micheli's Clathroidastrum ; all writers subsequent in- 

 cluded species of other genera. 



Key to the Species of Stemonitis. 



A. Sporangia connately united \. S. confluens 



. B. Sporangia at maturity distinct. 



a. Spore-mass grayish black or black. 



1. Epispore slightly warted, not reticulate . . z.S.fusca 



2. Epispore reticulate. 



i. Reticulations band-like . . . 5. S. virginiensis 

 ii. Reticulations delicate. 



* Sporangia short, jet black . 3. S. nigresccns 

 ** Sporangia longer, fuscous . 4. S. maxima 



b. Spore-mass rich brown ; sporangia tall, 25 mm. or larger. 



1 . Columella central . . . . 6. S. morgani 



2. Columella eccentric, twisted . . -7- S.fenestrata 



c. Sporangia dark brown, shorter, gregarious, spores nearly smooth, 



12. 6". pallida 



d. Spore-mass ferruginous. 



I. Spores smooth or nearly so. 



i. Sporangia pale ferruginous, crowded, stipe not pol- 

 ished . . . . . . 10. S. smitJiii 



ii. Sporangia clavate, darker when fresh, stipe polished, 



1 1 . S. carolinensis 

 I 



