STEMONITIS] STEMONITACEAE 143 



Capillitium scanty, colourless, branching from a short 

 columella ; sporangia very minute. (23) Echinostelitjm. 



Fig. 31. — Echinostelium minutum de Bary. 



o. Group of three sporangia. Magnified 20 times. 



b Sporangium showing capillitium, all the spores 

 dispersed but two. Magnified 280 times. 



c. Spore. Magnified 500 times. 



Genus 18.— STEMONITIS Gleditsch Meth. Fung., 140, 

 tab. iv (1753). Sporangia cylindrical, stalked, fasciculate ; 

 the stalk extending within the sporangium to near the apex 

 as a columella (except in confluent forms) ; capillitium formed 

 of numerous threads radiating from all parts of the columella 

 and combined into a loose network, the ultimate branches 

 united into a superficial net. 



KEY TO THE SPECIES OF STEMONITIS. 



A. Spores grey, violet-grey, or rufous- violet : — 



a. Spores reticulated, surface net of capillitium with angular 



meshes. 1. S.fusca 



b. Spores minutely warted, almost smooth — 



Meshes of surface net rounded, 20 to 100 ^ or more wide 

 (imperfect in var. flaccida) ; spores 7 to 9 ll diam. 



2. S. splendens 



Sporangia confluent, without definite surface net, spores 

 9 to 11 fx. 3. S. confluens 



Meshes of smooth surface net angular, less than 20 ll 

 wide ; spores 7 to 8 //, diam. ; plasmodium white ; 

 sporangia clustered. 4. S. herbatica 



Meshes of uneven surface less than 20 fi wide; spores 

 7 to 8 jx diam. ; sporangia in scattered groups. 



5. S. pallida 



B. Spores pale ferruginous : — 



Spores 7 to 9 /x diam. ; plasmodium yellow. 



6. S. flavogenita 



Spores 4 to 6 //. diam. ; plasmodium white. 



7. S. ferruginea 



1. S. fusca Roth in Roem. & Ust. Mag. Bot., i. pt. 2, p. 26 

 (1787). Plasmodium white, in rotten wood, maturing at the 

 place of emergence. Total height 5 to 20 mm. Sporangia 

 cylindrical, obtuse, stalked, brownish-purple, at first closely 



