PLACODIUM | : PHYSIACEX 207 
Oswestry and near Shrewsbury, Shropshire; Llanfairfechan, Carnar- 
vonshire; Anglesea; Twycross, Leicestershire; Wimpole Park, 
Cambridgeshire; Norwich, Norfolk; near Ayton, Cleveland, York- 
shire; Brougham Castle, Westmoreland; Lamplough, Cumberland ; 
Hexham, Northumberland; near Edinburgh ; Gourock, Rentrew- 
shire ; Cupar, Fife; King’s Park, Stirling; Will's Braes, Forfarshire ; 
Nigg, Kincardineshire ; near Aberdeen; Dunkerron, Kerry ; Clare 
Island and Achill Sound, Mayo. 
Form flavocitrinum A. L. Sm.—Thallus indeterminate, 
minutely squamulose, thinnish, the squamules more or less 
pulverulent.—Lecanora flavocitrina Nyl. in Flora Ixix. p. 461 
(1886) & Cromb. Monogr. i. p. 372. Specimen not seen. 
Determined by Bouly de Lesdain (Lich. Dunk. p. 130 (1919)) as a 
‘form of Caloplaca citrina var. maritima, the squamulose character 
being due to the attacks of acarine and molluses. He proved the 
identity of his new plants with an original specimen from Staveley, 
Westmoreland. 
Hab. On schistose walls in an upland situation, Staveley near 
Kendal, Westmoreland. 
Form depauperatum A. L. Sm.—Thaillus effuse, the granules 
minute, scattered. Apothecia small, otherwise as in the type.— 
Lecanora citrina f. depauperata Cromb. in Grevillea xviii. p. 45 
(1889) & Monogr. i. 372. 
Euxsicc. Johns. n. 408 ; Larb. Lich. Hb. n. 128. 
A very poorly developed condition of the species. 
Hab. On granitic rocks in maritime regions.—Distr. Rare in the 
Channel Islands, N.E. and N.W. England and W. Ireland.—B. MW. 
Alderney ; Kylemore, Connemara, Galway. 
15. Pl. phloginum A. L. Sm.—Thallus eftuse, thin, minutely 
granular -leprose, in crowded areolate masses or sparsely 
scattered, citrine or greenish-yellow (K + purplish). Apothecia 
small, plane, becoming convex, golden-yellow at first, with a 
scarcely perceptible thalline margin (K + crimson); spores 
ellipsoid-oblong, 11-15 yp long, 5—9 p wide (usually about 
10x 5p). Parmelia citrina var. phlogina Ach. Meth. Lich. 
p- 180 (1803). Lecanora phlogina Nyl. in Mém. Soc. Sci. Nat. 
Cherb. v. p. 112 (1857); Cromb. in Journ. Bot. ix. p. 178 
(1871) & Monogr. i. p. 386 ; Leight. Lich. Fl. 223 ; ed. 3, p. 213 
Exsicc. Johns. n. 75; Larb. Lich. Hb. n. 57 & Cantab. n. 7. 
Differs in habitat from Pl. cttrinwm, with which it might be easily 
confused. The thallus is however less brightly coloured and less 
luxuriant, and the apothecia smaller, with the thalline margin thin 
and becoming excluded. 
Hab. On the trunks of old trees, generally ash or elm, rarely on 
old wood in maritime or inland districts.—Distr. Rare in the Channel 
Islands and throughout England.—B. M. St. Clement’s Bay, Jersey 
Penzance, Cornwall; near “Hastings, Sussex; Windsor Great Park, 
Berks; near Worcester; Pampisford and Great Wilbraham, Cam- 
bridgeshire ; Alston, Cumberland. 
