o4 



COLLEMACKI. 



[COLLEMA. 



Hah. On calcareous rocks and walls in upland hilly districts.— Dis^r. 

 Local and scarce in W. England, the S.W. HijxLlands, Scotlond, and 

 N.W. Ireland.— B. M. : Cleeve Hill, Somersetshire ; Shipton and near 

 Cirencester, Gloucestershire : Buxton, Derbyshire ; near Kendal, West- 

 moreland. Appin, Argyleshire. Kylemore, co. Galway. 



Fig. 13. 



CoUcma nif/rcsceiis, Ach. 

 FiTB spores, X 500. 



C. SYXECHOBLASXrS (Trevis. Xuov. 

 gen. CoUem. 1853). — Thallus variously 

 lobed. Apothecia lecanorine, rarely 

 biatorine ; spores narrow or fusiform, 

 usually pluriseptate (not muriform) ; 

 hy menial gelatine bluish with iodine. 

 Spermogones with jointed sterigmata. 



20. C. Laureri Xvl. ex Cromb. Journ. 

 Bot. 1873, p. 132.— Thallus inciso-lobed, 

 smooth or slightly granular, duU olive- 

 black (I-|- reddish, when dry) : lobes some- 

 what dilated, rounded, ascending, crowded, 

 imbricate and undulate in the centre, more 

 or less depressed at the circumference, erect 

 and nearly entire at the margins. Apo- 

 thecia moderate, sessile, plane, reddish-brown or dark-red, the 

 margin entire or slightly crenate ; spores lineari-oblong, obtuse at 

 both apices, 3-septate, straight, 0,020-24 mm. long, 0,005-6 mm. 

 thick. — Cromb. Journ. Bot. 1874, p. 334 ; Leight. Lich. Fl. ed. 3, 

 p. 22. — S>/nec7iohlastiis comjdicatus Mudd, Man. p. 44, t. 1. f. 6. 

 SynecJwhlastus LaureriFlot. in Koerb, Syst. Lich. Germ. (1855) p. 414. 



Externally subsimilar to C. polycaiyon, but distinguished by the broader 

 lobes, and especially by the spores being more obtuse. The thallus 

 radiates from the centre, and accordincr to Koerber is white-fibiillose- on 

 the underside. The apothecia are scattered and chiefly marginal. We 

 haye seen only a small specimen very sparingly fertile. 



Hah. On limestone walls in upland districts. — Distr. Local in N. Eng- 

 land, where according to Mudd it is abundant near the High Force Inn, 

 Teesdale ; if really British, should be detected elsewhere. — B. M. : Tees- 

 dale, Durham. 



21. C. nigrescens Ach. Lich. Univ. (1810) p. 646.— Thallus sub- 

 monophvllous, rouncUy lobed, radiateiy rugoso-plicate, olive- or black- 

 ish-green ( I -f reddish, when dry) ; lobes broad, smooth or granulose, 

 depressed at the circumference, more or less ascending in the centre, 

 entire or slightly crenate at the margins. Apothecia small, plane, 

 at length convex, crowded, the margin entire ; spores fusiformi- 

 cyliudrical, pluri-septate, 0,0034-42 mm. long, 0,005 mm. thick. — 

 Hook. Fl. Scot. ii. p. 71 ; Sm. Eng. Fl. v. p. 211 ; Tavl. in Mack. 

 Fl. Hib. ii. p. 110 ; Cromb. Lich. Brit. p. 6 : Leight. Lich. Fl. p. 24, 

 cd. 3, p. 24. — Synechohlastus nirp'escens Mudd, Man. p. 42, t. i. f. 5. 

 Lathraqwrii niqresc^ns Gray, Nat. Arr. i. p. 309. Lichen niqrescens 

 Huds. Fl. Angi (1762) p. -150 ; With. Arr. od. 3. iv. p. 74 : Eng. Bot. 



