COLLEMACEI. 



[COLLEMA. 



Fig. 13. 



Collcma nigrescens, Ach. 

 Fire spores, X 500. 



^ g 



d [ -B M. : Cleeve Hill, Somersetshire; Shipton and near 

 CicesteGioucestershire; Burton,' Derbyshire; near Kendal, West- 

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



C SYNECHOBLASTUS (Trevis. Nuov. 

 gen. Collem. 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 Nyl. ex Cromb. Journ. 

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

 smooth or slightly granular, dull 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. M. ed. 3, 

 p. 22. Synechoblastut complicatus Mudd, Man. p. 44, t. 1. f. 6. 

 SynechollastusLaureriFlot. in Koerb. Syst. Lich. Germ. (1855) p. 414. 



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

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

 radiates from the centre, and according to Koerber is white-fibrillose on 

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

 have seen only a small specimen very sparingly fertile. 



Hob. 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- 

 monophyllous, roundly lobed, radiately rugoso-plicate, olive- or black- 

 ish-green (I -(-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- 

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

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

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

 ed. 3, p. 24. Synechoblastus nigrescens Mudd, Man. p. 42, t. i. f. 5. 

 Lathragium nigrescens Gray, Nat. Arr. i. p. 399. Lichen nigrescens 

 Huds. Fl. Angl. (1762) p. 450 ; With. Arr. ed. 3, iv. p. 74 ; Eng. Bot, 



