182 



LICHEXACEI. 



[roccelxa. 



34. ROCCELLA DC Fl. Fr. ii. (1805) p. 334.— Thallns sub- 

 fruticiilosc, usuallv opaque and smoothish, someiivhat tough, atten- 

 uate at the apices, con- 

 oolorous on both sides, 

 medullary layer dense. 

 Apothecia lateral, leci- 

 deine or irregular,naked 

 or pruinose ; hypo- 

 thecium thick, black ; 

 spores oblong or fusi- 

 form, straight or curved; 

 hyraenial gelatine wine- 

 red or wine - yellow, 

 or sometimes slightly 

 bluish with iodine. 

 Spermogones lateral, 

 with acicular, curved 

 Bpermatia. 



The thalhis is more or 

 less fruticulose from a 

 common base,andiu some 

 ppecies is of cou*iderable 

 size. It is whitish, raiely 

 brownish, in colour, and 

 iirm, though sometimes 

 from tenuity becoming 

 Haccid. The cortical and 

 gonidial systems, as ob- 

 served bv Xvlander. Svn. 

 i. p. 256 ■((:/;•. Flora.] 866, 

 I'.'S), form a confluent 



Fig. 37. 



Boccella phi/copsis Ach. — a. Section of external 

 portion of the thallus, showing tlie cortical and 

 gouidial layers and a sinall exterior portion of 

 the medulla, x2(X). b Gonidia, x350. c. Ver- 

 tical section of an apotbecium. X 30. d. Tbeca 

 and parapbysis, X350. e. Spores. XoOO. /. 

 Vertical section of a sperniogone, X 30. ff. 

 Sterigmata and spermatia, X 500. 



P 



layer, the cortex, wliich 



is destitute of an epithallus, consisting of medullary filaments thickened 



towards the surface and there densely parallel, external to which are seen 



granular element^, while internally and immediately beneath the cortex 



are the gonidia. The apothecia are lecideine or variously deformed, often 



as in IJirinn, sometimes as in Chiodecton, with the paraphyses slender or 



nearly moderate, and not unfrequently bifurcate. 



1. R. phycopsis Ach. Lich. Univ. (1810) p. 440.— Thallus 

 rounded or slightly compressed, ven* much branched and densely 

 csespilose, whitish or glaucous-brown, more or less sorediiferous ; 

 branches subsimple or dichotomously divided (Ca CI + reddish, sore- 

 dia — , medulla I -f bluish). Apothecia small, lecideine, black, naked 

 or slightly pruinose, somewhat prominent or appressed ; spores fusi- 

 formi-oblong, 0.012-16 mm. long, 0,n03-4 mm. thick. — Xyl. Syn. 

 i. p. 259. t. 8. f. 3 ; Gray, Nat. Arr. i. p. 426 : Cromb. Lich. Brit, 

 p. 22 : Leight. Lich. Fl. p. 81, ed. 3, p. 74. — lioccdla tincioria /3. 

 phycopsis Mudd, Man. p. 75. LicJien fucoides Dicks, Crypt, fasc. ii. 

 p, 22. LicJun BocccUa "With. Arr. ed. 3, iv. p. 42. BocxiUa tinc- 

 ioria 8m. Eng. Fl. v. p. 221 ; Mudd, Man. p. 75; Leight. Lich. Fl. 



