PHYSCIA | PHYSIACEE 235 
var. hypoleuca Ach. Syn. Lich. p. 211 wor: Tayl. 1. ¢. pro 
parte. 
An exotic variety, sometimes given non rank, which has 
become naturalized in S.W. Ireland. The apothecia when present 
are crowded and rather large. 
Hab. On rocks in shady situations.—B. M. Dunkerron, Kerry. 
B. Cortex fibrous on lower surface, plectenchymatous above. 
6. Ph. pulverulenta Nyl. in Act. Soc. Linn. Bord. sér. 3, i. 
p- 308 (1856).—Thallus suborbicular, of appressed somewhat 
stellate contiguous multifid firm opaque lacini, obtuse and 
incised-crenate, pale-greyish or greyish-brown, greenish when 
moist, more or less white-pruinose ; beneath black, covered with 
rather long stiff black rhizinze which bristle with short branchlets 
(K —). Apothecia sessile, moderate in size or becoming large, 
the disc brownish-black, greyish-pruinose or naked, the margin 
taick, entire, sometimes crenate or scantily proliferous ; spores 
large, 20-36 p long, 12-20 p thick.—-Cromb. Lich. Brit. p. 38 ; 
Leight. Lich. Fl. p. 146; ed. 3, p. 135; £. panniformis Cromb. in 
Journ. Linn. Soc. xvii. p. 571 (1880) & Monogr. i. p. 306; 
f. deminuta Cromb. in Journ. Bot. xx. p. 275 (1882) & Monogr. i. 
p- 306. Muscus licheniformis viridis &e. Buddle Hort. Sice. i. 
fol. 6, n. 10 in Herb. Sloane. Lichenoides arboreum, crusta foliosa 
virescente &c. Dill. in Ray Syn. ed. 3, p. 74, n. 73 (1724). 
Lichenoides glaucum orbiculare, segmentis latiusculis, scutellis nigris 
Dill. Hist. Muse. p. 177, t. 24, fig. 71 a, p (1741) pro parte. 
Lichen pulverulentus Schreb. Spic. Fl. Lips. p. 128 (1771). Lichen 
stellaris var. Huds. Fl. Angl. p. 448 (1762); With. Arr. ed. 3, 
iv. p. 31. Parmelia pulverulenta Ach. Meth. Lich. p. 210 (1803); 
S. F. Gray Nat. Arr. i. p. 443; Hook. FI. Scot. ii. p. 55 & in 
Sm. Engl. Fl. v. p. 201; Tayl. in Mackay Fl. Hib. ii. p. 141. 
Borrera pulverulenta Mudd Man. p. 110 (1861). 
Fxsicc. Bohl. n. 69; Johns. nos. 127, 404; Larb. Lich. Hb. 
n. 10 & Lich. Cantab. n. 12; Leight. n. 49; Mudd n. 82. 
Generally recognized by the white pruina on the thallus and 
apothecia which is chiefly visible in the dry condition; the lacinix 
are rather thick and of a dull green when moist. Both thallus and 
apothecia are variable ; the lacinie are appressed and contiguous at 
the circumference, but towards the centre are often imbricate with 
minute proliferations mostly from the edges of the lobes. The allied 
forms panniformis and deminuta have “small apothecia and small 
lobes, crowded and imbricate in the former, rather sparsely scattered 
in the latter, evidently growth conditions. The upper cortex is 
indistinctly plectenchymatous and granulose, the lower is fibrous, of 
dark-brown hyphe parallel with the long axis of the lobes. 
Hab. On trunks and branches of trees and on palings, rarely on 
stone walls, chiefly in cultivated lowland and upland districts.— 
Distr. General and usually common throughout the British Isles.— 
B. M. Guernsey; near Withiel, Cornwall; near Torquay, Moreton 
