COLLEMA.J COLLEMEI. 51 



Lich. Brit. p. 5, and C. subplicatile, var. meisolobitm Nyl., Cromb. Jouru. 

 Bot. 1874, p. 334 ; but these are connected by intermediate states. The 

 apothecia are rare and scarcely seen in the larger condition. 



Hob. On calcareous walls and rocks, rarely among mosses on the 

 ground in upland districts. Distr. Probably general and common in the 

 hilly and mountainous tracts of Great Britain and Ireland. B. M. : 

 Sha'nklin, Isle of Wight ; Plymouth, Elburton, Paington, Ogwell, and 

 near Kingsbridge, S. Devon ; St. Minver, Cornwall ; Bathanipton Downs, 

 Weston-super-Mare, and Cheddar Cliffs, Somersetshire ; Leigh Woods, 

 near Bristol, Gloucestershire ; Tenby, Pembrokeshire ; Beaumaris, Island 

 of Anglesea ; near Buxton, Derbyshire ; Pentregaer, Oswestiy, Shrop- 

 shire ; Redcar, Cleveland, Yorkshire ; near Whitehaven, Cumberland. 

 Appin, Argyleshire ; Killin and Ben Lawers, Perthshire ; S. of Fort 

 William, Inverness-shire. Killarney, co. Kerry ; near Kyleuiore and 

 Recess, Connemara, co. Galway. 



17. C. melaenum Ach. Lich. Univ. (1810) p. 636. Thallus de- 

 pressed, lacero-laciniate, greenish- or olive-black (I wine-red in thin 

 section); laciniae more or less elongate, somewhat broad and imbricate, 

 the margins elevated, undulate, crisp and crenate. Apothecia mode- 

 rate, sessile or slightly elevated, submarginal, plane, reddish-brown 

 or blackish, the thalline margin somewhat granulate ; spores ovoid, 

 2-3-septate and irregularly divided, 0,021-27 mm. long, 0,009- 

 11 mm. thick. Mndd, Man. p. 37: Cromb. Lich. Brit. p. 5 

 pro parte ; Journ. Bot. 1874, p. 334 ; Leight. Lich. Fl. p. 19 pro 

 parte, ed. 3, p. 20. Lichen melcenus Ach. Prodr. (1798) p. 130. C. 

 atiriculatumvsiT.pinguescc-ns Nyl. Flora, 1872, p. 353 ; Cromb. Journ. 

 Bot. 1873, p. 133 ; Leight. Lich. Fl. ed. 3, p. 17 (cfr. Nyl. Flora, 

 1883, p. 534). 



The depressed orbicular thallus, and the form of the laciniae readily 

 distinguish this from the allied species. In favourable situations it is 

 often considerably expanded, and then in old plants becomes centrifugal. 

 The apothecia are not uncommon, generally numerous, situated 

 towards the margins, and at length slightly convex and concolorous 

 with the thallus. On the sterile thallus is rarely seen a parasitic Obryzum, 

 which must not be confounded with the spermogones. 



Hob. On calcareous rocks and old walls in maritime and upland 

 districts. Distr. Local and scarce inN. England, the W., Central, audN. 

 Highlands of Scotland. B. M. : Near Buxton, Derbyshire ; Teesdale, 

 Durham; Kendal, Westmoreland; near Alston, Cumberland. Island of 

 Lismore and Appin, Argyleshire ; Killiu, Ben Lawers, and Craig Tulloch, 

 Perthshire ; Craig Guie and Morrone, Braemar, Aberdeenshire ; Coygach, 

 Sutherlandshire. 



Form 1. marginale Ach. Lich. Univ. (1810) p. 637. Thallus 

 elongato-laciniate, Iacinia3 narrow, canaliculate, the margins crisp 

 and crenate. Apothecia marginal, scattered, the thalline margin 

 prominent and entire Mudd, Man. p. 37; Cromb. Journ. Bot. 1874, 

 p. 334 ; Leight. Lich. Fl. ed. 3, p. 21. Collema marginale Hook. Fl. 

 Scot, ii. p. 71 ; Engl. Fl. v. p. 210 ; Tayl. in Mack. FL Hib. ii. p. 109. 

 EncJtyUum marginal*, Gray, Nat. Arr. i. p. 397. Lichen marginulis 



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