GRAPHISJ GRAPHIDACE.E 249 



0,020-45 mm. lon<^, 0,007-010 mm. thick ; spermogones with 

 minute spermatia 0,002-3 mm. long, 0,001 mm. thick. — S. F. 

 Gray Nat. Arr. i. p. 502 (excl. syn. Engl. Bot.) ; Hook. Fl. 

 Scot. ii. p. 43 ; Leight. Lich. Fl. p. 363 ; ed. 3, p. 428 (inch 

 ff. diffusa, varia, flexuosa, and divaricata) ; Mudd Man. p. 237 

 (incl. vars. abietina (now Scha3r.), varia, flexuosa, and divaricata) ; 

 Cromb. Lich. Brit. p. 96. G. serpentina Leiglit. in Ann. & Mag. 

 Nat. Hist. ser. 2, xiii. p. 269, t. 6, f. 20 (incl. vars. diffusa, 

 varia, flexuosa, and divaricata (non Ach.)). Lichenoides crusta 

 tenuissima, peregrinis velut litteris inscripta JJill. Hist. Muse, 

 p. 125, t. 18, f. 1b (1760). Lichen scriptus L. Sp. Plant, p. 1140 

 (1753); Lightf. Fl. Scot. p. 800; With. Arr. ed. 3, iv. p. 4. 

 Opegrapha scripta Ach. Meth. p. 30 (1803); Grev. Fl. Edin. 

 p. 353 pro parte ; Hook, in Sm. Engl. Fl. v. p. 147 pro parte; 

 Tayl. in Mackay Fl. Hib. ii. p. 106 pro parte. 



Exsicc. Leight. nos. 19 (pro parte), 21 ; Larb. Lich. Caesar, 

 n. 88. 



A very variable species in the form and appearance of the thallus 

 and apothecia. In the typical plant the thallus is developed beneath, 

 or confused with, the outer layers of the cortex and is usually 

 determinate, sometimes limited by a black line, the f. limitata of 

 continental lichenologists {Opegrapha limitata Pers. in Ust. Ann. vii. 

 p. 30 (1794)). The apothecia are usually very long and narrow, some- 

 times almost thread-like (var. tenerrima Ach. I. c. p. 266), naked or 

 subpruinose, straight or curved (f. flexuosa Leight. II. c), simple, 

 sparingly scattered over the thallus (f. diffusa Leight. II. c. ; var. 

 abietina Mudd I. c), or branched, crowded and lying in all directions 

 (f. varia Leight. II. c). In f. divaricata Leight. II. c. they are rather 

 short, and distinguished by one or more lateral branches growing out 

 at right angles, but this character is confined to very few of the 

 apothecia present on any specimen. The more definitely marked 

 varieties are recorded below. The spores are normally colourless ; 

 the brown colouration, as in some other cases, is largely due to 

 arrested growth or to premature decay. 



Hab. On bark of various trees. — Distr. Common in England and 

 Ireland, less frequently recorded from Scotland. — B. M. Jersey ; 

 Withiel, Cornwall ; Torquay, Devon ; New Forest, Hants ; near 

 Handcross, Ardingly, Danny, Midhurst, St. Leonard's Forest, Sussex ; 

 Codham Hall and White Colne, Essex ; Bath, Somerset ; Chepstow, 

 Monmouthshire ; Gopsall and Twycross, Leicestershire ; Dolgelly and 

 Barmouth, Merioneth ; Gloddaeth, near Conway, Trefriw and Gwydir 

 Woods, Bettws-y-Coed, Carnarvonshire; Kildale, Airyholme Wood, 

 Easby Wood and Newton Wood, Cleveland, Hobhole and Ay ton, 

 Yorkshire ; near Glasgow, Lanarkshire ; Aberfeldy, Perthshire ; 

 Enniskean, Glenbower, Castle Bernard, Cork ; Killarney, Kerry ; 

 Glenstale, Tipperary; Doughruagh Mt., Connemara, Gal way. 



Form recta Nyl. Lich. Scand. p. 252 (1861).— Thallus in 

 elongated patches, often limited by a black line. Apothecia 

 numerous, arranged in somewhat straight subparallel lines. — 

 Cromb. Lich. Brit. p. 96 ; Leight. Lich. Fl. p. 365 ; ed. 3, 

 p. 429 ; f. betuligna Cromb. I. c. ; f. liorizontalis Leight. II. c. 



