110 



LICHENACEI. 



[sTEBEOCAULOJr. 



Vi 



J 



Tribo V. STEREOCAULEI Nyl. Mc'm. Soc. Chorb. iii. 

 (1855) p. 170. 



Thallus coispitose, erect or decumbent, with solid fruticulosc 

 podetia, to which are affixed fragile, more or less evanescent gra- 

 nules, usually bearing cephalodia, iuternally with chondroid axis. 

 Apothecia lecideine, rarely lecanorine, terminal and lateral, para- 

 physes discrete : spores Snfe, sometimes Gnue, variously septate, very 

 rarely solitary and raurali-divided, subfusiform, cylindrical or oblong, 

 colourless. Spermogones immersed, with simple sterigmata. 



Though resembling the Sphcerophorei in the fraticulose habit, this 

 tribe is far separated by the grauidose thallus and by the structure of the 

 apothecia. From the preceding, to which it is closely aUied, it differs in 

 the absence of the thick subhymenial stratum. As observed by Nylauder 

 (Lapp. Or. p. 177), it precedes, like the Piluphorei, the Cladoniei, since 

 the gi'anulose thallus expresses a lower type in the series. 



29. STEREOCAULON Schrcb. Gen. PI. (1791) p. 768 : Xyl. Syn. 

 i. (1860) p. 23n. — Podetia branched, somewhat rounded, covered Or 

 sprinkled with gra- 

 nules of various forms, 

 internally with a car- 

 tilaginous axis formed 

 of longitudinal conglu- 

 tinate chondrohyphse, 

 to which are affixed 

 the external portions 

 of the thallus, viz. a 

 corticali-gonidial and 

 an arachnoid medul- 

 lary layer. Apothe- 

 cia biatorine, blackish- 

 brown or pale brown- 

 ish, rarely lecanorine, 

 black : hypothecium 

 colourless ; spores 8nfe 

 or 6noe (in subclavate 

 thecoe), fusiformi-cylin- 

 drical, "6- or pluri-sep- 

 tate ; paraphyses dis- 

 tinct, slender or mode- 

 rate ; hj-menial gelatine bluish with iodine. Spermogones lateral 

 or subterminal in pale conceptacles, blackish at the apices, with 

 spermatia aciculari-bacillar, straight, or longer and slightly curved. 



Many plants belonging to this genus have an elegant appearance witli 

 their fraticulose granidate podetia and numerous brown or dark apothecia. 

 The podetia, especially in barren specimens, are sometimes whitish 

 sorediato-capitate. The apothecia, which arise from the granides, are at 

 first punctiformi-impressed, and tlien lecanoroid, becoming immediately 

 lecideine (biatonne). C)ur British species, wliich belong to the subgenus 

 £iisfercniaidon, hiive thf thalHm' reactions K+yellow, CaClZ, except in 

 6'. coralloides, where the chondroid axis is K-f- yellow. 



d 



) 



\»>uM\ 



yt^j.j- 



Fig. 33. 

 Sfcreocaulon corallvides Fr. — a. Vertical section of 

 an apotliecium, x30. h. Theca and paraphysis, 

 X350. c. iSpores, x500. d. Vertical section 

 of a Touug spermogone, x30. c. Sterigmata, 

 and,/", spermatia, XoOO. 



