PHYSCIA | PHYSIACE 239 
(1810) ; Hook. Fl. Scot. ii. p. 55 & in Sm. Engl. FI. v. p. 201. 
Borrera obscura var. chlorantha Mudd Mi an. p. 110 (non Ach.). 
Exsicc. Mudd n. 81. 
A variable plant, but distinguished by the absence of pruina on 
the thallus and by the light-coloured under surface. The cortex of 
the upper surface is somewhat obscurely plectenchymatous, with 
-small cells; that of the lower is fibrous. The rhizin vary from 
light grey to black; generally they are greyish or brownish. 
Hab. On trees by roadsides, ete., in lowland and upland districts. 
—Distr. Seen only from a few localities in N. England and the 
Grampians, Scotland.—Bb. M. Near Ayton, Cleveland, Yorkshire ; 
Achmore, Killin and Ben Lawers, Perthshire; Monaltrie House, 
Ballater and Countesswells, Aberdeenshire. 
Var. aipolia Nyl. Lich. Scand. p. 111 (1861).—Laciniz of 
the circumference more plane than in the species, beneath 
whitish or grey (K+yellow).—Physcia aipolia Nyl. in Flora liii. 
p- 58 (1870) ; Cromb. in Journ. Bot. vill. p. 97 (1870), in Journ. 
Linn. Soc. Bot. xvii. p. 571 (1880) (incl. f. acrita) & Monogr. i. 
p. 313. Ph. stellaris var. acrita Cromb. Lich. Brit. p. 39 (1870). 
Lichenoides cinereum, seqmentis argutis stellatis, scutellis nigris 
| Dill. Hist. Muse. p. 176, t. 24, f. 70 a, B (1761). Lichen stellaris 
Huds. Fl. Angl. p. 448 (1762) (non L.) fide Crombie. L. aipolius 
Ach. Lich. Suec. Prodr. p. 112 (1798). 
Hesice. Croall. n.592. 
Distinguisned from the species by the more flattened thallus, 
which in age becomes wrinkled in the centre; but chiefly by the 
reaction of the medulla with potash, which gives a faint-lemon yellow. 
Hab. On trees, rarely on calcareous walls, in maritime and inland 
districts.—Distv. Rather rare throughout the British Isles.—B. MW. 
Penzance, Cornwall; Ilsham Valley, Torquay, and Linton, Devon; 
Shanklin, I. of Wight; near Lewes, Sussex; Hafod, Cardiganshire ; 
Dolgelly, Merioneth; near Kendal, Westmoreland; Appin, Argyll; 
Killin and Ben Lawers, Perthshire ; Castleton of Braemar, Aberdeen- 
shire; Applecross, Rossshire ; Kylemore and Loch Inagh, Connemara, 
Galway. 
Form anthelina Nyl. Lich. Scand. p. 111 (1861).—Thallus 
with narrower lacinize which are more apart, long, rather convex, 
and with more developed black rhiziniz, beneath greyish-brown 
(K +2"). Ph. aipolia var. anthelina Cromb. in Grevillea xv. 
p. 78 (1887). Lichen anthelinus Ach. Lich. Suec. Prodr. p. 111 
(1798). 
This form is identical with Lichen ambiguus Ehrh. Pl. Crypt. 
n. 207 (1785) nomen nudum, the name adopted by continental lichen- 
ologists. ae as in species and varieties the margin of the apothecium 
becomes crenulate with age. The reaction with potash allies it with 
var. aipolia. 
Hab, On trees in maritime and inland districts.— Distr. Rare in 
S. England and S.W. Ireland.—B. M. Isham Valley, Torquay, Devon ; 
near Ryde, I. of Wight; Henfield, Sussex; Muckruss Demesne, 
Killarney, Kerry. 
