PHYSCIA | PHYSIACE® 243 
tinguished by the extensive soredial development, the whole centre 
of the thallus frequently becoming leprose; occasionally it is more 
isidiose (Parmelia columnaris). The upper cortex is plectenchymatous, 
the lower is indistinctly fibrous, being formed of rather thick-walled 
branching hyphé subparallel to the long axis of the lobes. 
Hab. On the trunks of trees, often in orchards, and on tiled roofs 
in maritime and inland districts.—Distr. Somewhat rare in the 
Channel Islands, 5. and Central England, N. Wales, S. and W. Ireland, 
not seen from Scotland.—B. M. Rozel-and St. Martin’s, Jersey ; 
Guernsey; Penzance, Cornwall; near Plymouth, Devon; near South- 
ampton, Hants; Ryde, I. of Wight; Brighton, Henfield, Sedlescombe, 
Glynde, near Lewes and Hurstpierpoint, Sussex; near Maidstone and 
Tunbridge Wells, Kent; Saffron Walden and Epping Forest, Essex ; 
West Haddon and Buckly Folly, Northamptonshire; Twycross, 
Leicestershire ; Barmouth, Merioneth; Carigaline near Cork; Dun- 
kerron, Kerry; Tervoe, Limerick; Kylemore Lake, Connemara, 
Galway. 
Form elegans Cromb. Monogr. i. p. 317 (1894).—Thallus 
glaucous-white, the lacinie long and narrow, branched and 
spreading, frequently isidiose at the margins.— Var. elegans Ny]. 
ex Leight. Lich. Fl. ed. 3, p. 139 (1879). 
Easicc. Larb. Lich. Hb. n. 88. 
Hab. On rocks in a maritime district—B. M. S. of Kylemore 
Lake, Connemara, Galway (the only British locality). 
12. Ph. cesia Nyl. in Act. Soc. Linn. Bord. sér. 3, i. p. 308 
(1856).— Thallus normally orbicular-stellate, closely adnate, 
formed of narrow dividing radiating laciniz, convex, contiguous, 
and spreading at the tips, light- or dark-grey, sprinkled with 
round whitish-grey soralia; beneath pale, with brown rhizine 
(K + yellow). Apothecia rare, chiefly central, rather small, 
naked or pruinose, the margin prominent, entire or crenulate ; 
spores oblong, 16-23 p long, 9-13 p thick.—Cromb. Lich. Brit. 
p. 39. Ph. stellaris var. cesia Leight. Lich. Fl. p. 152 (1871) ; 
ed. 3, p. 141. Lichenoides cinereum, segmentis argutis stellatis, 
scutellis nigris Dill. Hist. Muse. p. 176, t. 24, fig. 70 0 (1741). 
Lichen cesius Hoffm. Enum. Lich. p. 65, t. 12, fig. 1 (1784); 
Engl. Bot. t. 1052. Lichen Psora Dicks. Pl. Crypt. fase. iii. 
p. 17 (1793) ; With. Arr. ed. 3, iv. p. 26. Parmelia cexsia Ach. 
Meth. Lich. p. 197 (1803); 8. F. Gray Nat. Arr. i. p. 443; 
Tayl. in Mackay FI. Hib. ii. p. 147. Squamaria cesia Hook. in 
Sm. Engl. Fl. v. p. 196 (1833). Borrera cesia Mudd Man. 
p. 107 (1861). 
Exsicc. Johns. n. 252; Leight. n. 323. 
Distinguished by the stellate outline and by the presence of 
soralia, though in some specimens one or other of these characters is 
obscure. The lower cortex is fibrous formed of brownish irregularly 
parallel hyph, with occasional cell formation. 
Hab. On walls, roofs and boulders in lowland and upland districts. 
—Distr. General though not common throughout the British Isles, 
R 2 
