D I DERM A 143 



there is none. What may occasion such divergence of statement none 

 may say; such forms as come in so far from our western mountains 

 have no columella. 



17. DiDERMA ASTEROIDES L/j/. 



Plate XVIIL, Figs. 3, 3 a 



1902. Diderma aster aides List, Jour. Bot., XL, p. 209. 

 1911. Diderma asteroides List., Myceiozoa, 2nd ed., p. 113. 



Sporangia globose or ovoid-globose, the apex more or less acuminate, 

 sessile, sometimes narrowed at the base to a short, thick stalk, brown 

 or chocolate tinted, marked at the apex by radiant lines, and at length 

 dehiscent by many reflexing lobes revealing the snow-white adherent 

 inner peridium on the exposed or upper side; columella also white, 

 globose or depressed-globose; capillitium generally colorless, some- 

 what branched, especially above; spores dark violaceous, verruculose, 

 10-12 II. 



Oregon, the Three Sisters Mountains; Colorado; California. 



A very beautiful species, recognizable at sight; when unopened, by 

 the peculiar chocolate brown, the sporangia smaller than in D. radi- 

 atum. When opened, the snow-white flower-like figure, flat against 

 the substratum, is definitive. Very near number 16 preceding; the 

 dehiscence more regular. 



18. Diderma floriforme (Bull.) Pers. 



Plate VIIL, Figs. 1, 1 a, 1 b. 



1791. Sphaerocarpus floriformis Bulliard, Champ., p. 142, t. 371. 

 1794. Diderma floriforme (Bull.) Persoon, Rom. N. Mag. Bot., p. 89. 



Sporangia crowded, generally in dense colonies, globose, smooth, 

 ochraceous-white, stipitate, the peridium thick, cartilaginous, splitting 

 from above into several petal-like lobes, which become speedily re- 

 flexed exposing the swarthy spore-mass, the inner peridium not 

 discoverable, inseparable ; stipe concolorous, about equal to the sporan- 

 gium ; hypothallus, generally well developed, but thin, membrana- 

 ceous, common to all the sporangia; columella prominent, globose or 

 cylindric, often constricted below, and prolonged upward almost to 

 the top of the spore-case; capillitium of slender, delicate, sparingly 



