arthonia] arthoniace.^ 215 



18. A. radiata Ach. Lich. Univ. p. 144 (1810) (incl. vars.). — 

 Thallus developed under the bark, t'orining Avhitish or greyisli 

 determinate patches, sometimes witli a dark outline. Apothecia 

 small, dark-brown, rough, innate, clustered in substellate or 

 radi.-ite groups, pale within, the epithecium dark-brown ; spores 

 linear-elavate, 3-septate, rounded at the ends, the cells equal in 

 .size, colourless, sometimes with a clear epispore, 0,012-20 mm. 

 long, 0,004-6 mm. thick ; hymenial gelatine blue then violet, 

 the asci and spores wine -red, with iodine. — A. astroidea Ach. in 

 Schrad. Neu. Journ. Bot. i. 3, p. 17, t. 4, f. 4 (1806) & Syn. p. G 

 (1814) (excl. var. anastomosans) ; Hook. Fl. Scot. ii. p. 36; S. F. 

 Gray Nat. Arr. i. p. 479 ; Leight. in Ann. Mag. Nat. Hist. ser. 2, 

 xiii. p. 438, t. 8, f. 32 (1854) & Lich. Fl. p. 396 ; ed. 3, p. 419 ; 

 Mudd Man. p. 246 (incl. var. anastomosans (non Ach.)) ; Cromb, 

 Lich. Brit. p. 103 pro parte. Opegrapha radiata Pers. in Ust. 

 A.nn. Bot. vii. p. 29 (1794). 0. astroidea Ach. Meth. p. 25 

 (1803); Engl. Bot. t. 1847. Liclien astroites Ach. Lich. Suee. 

 Prodr. p. 24 (1798). 



ExsicG. Baxt. Stirp. Crypt, n. 22 ; Mudd nos. 227, 229 (as 

 var. anastomosans) ; Leight. n. 289 ; Larb. Lich. Hb. n. 112. 



Hab. On smooth bark of trees in wooded regions. — Distr. General 

 and common throughout the British Isles. — B. M. Sark ; St. Breock, 

 CornwpJl ; Ilsham, Torquay ; Lydford, near Lustleigh and Ullacombe, 

 Devon ; Lyndhurst, New Forest, Hants ; St. Leonard's, Hurstpier- 

 point and Glynde, Sussex ; Ightham, Kent ; Shiere, Surrey ; Epping 

 Forest, Hockley Woods and Ulting, Essex ; Windsor Forest, Berks ; 

 Gopsall Park, Leicestershire ; Malvern, Worcestershire ; Edderton 

 Wood, Montgomeryshire ; Builth, Brecknockshire : Barmouth, 

 Merioneth ; Bettws-y-Coed, Carnarvonshire ; near Buxton, Derby- 

 shire ; Cottishall, Norfolk ; Easby Wood and Cliffrigg, Cleveland, York- 

 shire ; Hexham, Northumberland ; near Edinburgh ; Pearsie, Forfar- 

 shire ; Glen Falloch, Glen Lochay, Finlarig, Killin and Aberfeldy, 

 Perthshire ; Appin and Barcaldine, Argyll ; Hill of Ardo and Morrone, 

 Braemar, Aberdeenshire ; Fort William, Invernessshire ; Applecross, 

 Ptossshire ; Kiilarney, Kerry ; Killaloe, Clare. 



Var. Swartziana Sydow Flecht. Deutschl. p. 243 (1887). — 

 Thallus whitish or olivaceous, subdeterminate. Apothecia black, 

 plane, clustered into irregular angular sometimes elongate shapes. 

 — Arthonia Swartziana Ach. in Schrad. Neu. Journ. Bot. i. 3, 

 p. 13, t. 4, f. 1 (1806); Engl Bot. t. 2079; S. F. Gray Nat. 

 Arr. i. p. 479 ; Hook, in Sm. Engl. Fl. v. p. 143 ; Tayl. in Mackay 

 Fl. Hib. ii. p. 104 ; Leight. in Ann. Mag. Nat. Hist. ser. 2, xiii. 

 p. 439 (1854) & Lich. Fl. p. 397 ; ed. 3, p. 420 (incl. A. astroidea 

 var. simulans Leight.). A. astroidea var. Swartziana Hepp Flecht. 

 Eur. n. 352 (1857); Mudd Man. p. 246; Cromb. Lich. Brit 

 p. 103. 



Exsicc. Mudd n. 228 ; Leight. n. 70. 



Differs from the species in the more compact ardellte, which are 

 irregular in outline rather than distinctly- stellate or radiate. When 



