18. CLADONIACEAE 



Thallus usually twofold, primary thallus crustose, granulosa, squaniu- 

 lose, or foliose, often soon disappearing, more or less differentiation into 

 layers, attached to the substratum by hyphal rhizoids or occasionally by true 

 rhizoids ; secondary thallus consisting of erect podetia, short or elongated, 

 simple or branched, corticate or non-corticate and hollow or solid. 

 Apothecia borne on the tips of the podetia or laterally, globose, cylindrical, 

 or irregular in shape ; proper margin well developed, thalHne margin usually 

 lacking ; asci 6-8-spored ; spores hyaline, non-many-septate, or muriform. 



Alga Protococcus, rarely a blue-green. 



A. Podetia short, usually simple, rarely branched ; apothecia terminal. 

 B. Apothecia black; hypothecium dark colored 39. Pilophoron 



B. Apothecia light colored; hypothecium hyaline 38. Baeomyces 



A. Podetia longer, usually much branched; apothecia terminal or lateral. 



C. Cephalodia rare ; podetia usually hollow, spores non-septate. 



40. Cladonia 

 C. Cephalodia common ; podetia solid, spores 3-more-septate. 



41. Stcreocaiilon 



38. Baeomyces Ehrh. Beitr. zur Nat. 4 :149. 1789. 



Thallus crustose, granulose, or squamulose, containing a thin upper 

 cortex of gelatinous hyphae, an algal and a medullary layer, but no lower 

 cortex, attached to the substrate by hyphal rhizoids. Podetia very short, 

 arising from the medullary layer of the thallus (endogenous), alga present 

 or absent. Apothecia globose or irregular in shape, light colored, single or 

 conglomerate, terminal on the podetia or rarely sessile on the thallus ; 

 proper margin present or apothecia becoming hemispherical and im- 

 marginate ; hypothecium hyaline ; paraphyses unbranched, distant ; asci 

 8-spored; spores hyaline, nonseptate or 1-3-septate. 



Alga Protococcus or occasionally a blue-green. 



1. Baeomyces rujus (Huds.) Rebent. Prodro. Fl. Neomarch. 315. 1804, 

 Lichen riifns Huds. Fl. Angl. 443. 1762. 

 Baeomyces byssoides (L.) Gart. 



Thallus greenish gray, pale yellowish gray, or grayish white, a rather 



(74^ 



