Arcyria 



245 



Family II. ARCYRIACEAE 



Sporangia simple, stalked or sessile; capillitium a network of 

 tubular threads branching at wide angles, smooth or ornamented 

 with spines, warts, cog-like prominences or half-rings, usually 

 abundant, sometimes scanty and of free threads in Perichaena 

 corticalis. 



Capillitium elastic; sporangia stalked, rarely sessile; spo- 

 rangial wall evanescent above, persistent below as a 

 cup. 

 Capillitium not elastic. 



Sporangia sessile, heaped; sporangial wall single, per- 

 sistent, papillose; capillitium closely warted. 

 Sporangia sessile, rarely stalked; sporangial wall 

 usually of two layers, at least at the base, the outer 

 layer thickened with angular granules. 



42. Arcyria 



43. Lachnobolus 



44. Perichaena 



Genus 42. ARCYRIA Wiggers, Pr. Fl. Holsat. 109. 1780. 



Sporangia stalked, sometimes sessile in A. occidentalis; sporan- 

 gial wall evanescent above, persistent below as a membranous 

 cup; stalk filled with spore-like cells; capillitium a more or less 

 elastic network marked with spines, warts, cog-like prominences 

 or half-rings, or with a broken reticulation; spores nearly smooth 

 or faintly warted. 



Type species: Stemonitis incarnata Pers. 



Spores 9-11 m diam.; sporangia red or yellow. 



Sporangia usually red, ovoid or short-cylindrical; 



sporangial wall reticulate. 

 Sporangia yellow, clavate or piriform; sporangial wall 

 papillose. 

 Spores 6-8 m diam. 

 Cup complete. 



Capillitium firmly attached to the cup. 

 Sporangia white, gray or yellowish. 



Sporangia cylindrical or ovoid, gray or 

 yellowish; capillitium closely spinulose or 

 warted. 

 Sporangia globose, yellow; capillitium with 



spines arranged in an open spiral. 

 Sporangia globose, white, on slender stalks; 

 cup about half the height of the sporan- 

 gium; capillitium closely spinulose or 

 warted, the warts usually arranged more 

 or less in close, spiral lines. 



\. A. ferruginea 

 2. A. vitellina 



3. A. cinerea 



5. A. pomiformis 



6. A. globosa 



