BY JOHN SHIRLEY, B.SC. 



107 



** Rigescentes — Main stems rigid. 



8 U. cornuta, Flot. 



Thallus pale yellow-brown ; like U, dasypoga in its long 

 secondary branches, but with more numerous tertiary ones ; 

 main stems stiff and sub-erect, secondary divisions often 

 ascending, the internodes on all but the finest ultimate 

 divisions being freely but not thickly covered with small 

 rough setag ; branches and ramules slightly curved. Main 

 stems with small, raised, white-punctured, papillagform 



Sn roughenings. Apothecia dirty rose-pink, concave, with 

 defined margin and cilial fringe. 



u Arching and sorediiferous terminations the main 

 characteristics. Fibrils in their medullary portion give K 

 flavescent ; I caerulescent or violascent. Soredia K very 

 frequently flavescent," Stirton on the Genus Usnea and 

 another Eumitria. 



Hab — Common, except in its v. rubiginea, Ach. 



9. U. florida L. (K— I— ) 



Thallus reddish, erect, nearly glabrous, more or less polished, 

 densely and more or less intricately branched at various 

 angles ; the branches more or less, in different instances, 

 divaricato — fibrillose, but not papillose ; soredia rare but 

 Sn seldom absent, and tinged a decided yellow by K. Apothe- 

 cia 2 — 4*5 m.m. with reddish-brown bare receptacle, densely 

 fringed with stiff cilia, and enamelled disk. Spores oblong, 

 ellipsoid or sub-spherical, simple, colourless, *0075 x *005 

 m.m. Theca? 8-spored, -03 — '0375 x -Oil m.m. Para- 

 physes closely agglutinated. 

 U. f. v. articulata, Stirton. 



10. U. articulata Ach. (K— I— ) 



Thallus white or yellowish, long, branched, fibrillose or not, 

 jointed or constricted ; main stems smooth, waxy, sub- 

 rigescent, divided into a series of turgid articulations as if 

 hollow or inflated, here and there showing ochraceous dis- 

 coloration, the articulations connected by a narrow but firm 

 white medullary thread ; secondary branches moderately 

 slender and tapering to very attenuate points. Apothecia 



