PILYSCIA. | PHYSCTEI. 311 
rate, sessile, brownish-black, cxsio-pruinose or naked, the thalline 
margin entire or crenate; spores 0,016—24 mm. long, 0,008-11 mm. 
thick.—Cromb. Grevillea, xv. p. 78..-Parmelia stellaris Hook. Fl. 
Scot. ii. p. 55 pro parte; Sm. Eng. Fl. v. p. 201 pro parte. Lichen 
stellaris Linn. Sp. Pl. (1753) p. 1144; Ach. Prodr. p.111. Borrera 
obscura (3. chloantha (non Ach.) Mudd, Man. p.110. Physcia retro- - 
gressa Stirt. Trans. Glasg. Soc. Nat. 1875, p. 85 vix differt.—As - 
observed by Acharius (Meth. p. 209) the synonymy was then (as it 
still is) for the most part doubtful. It is, however, the plant of 
Linneus according to specimens in his herbarium.—Brit. Ews.: 
Mudd, n. 81. 
Distinguished from P. pulverulenta and its varieties by the smaller, 
epruinose thallus, which does not become greenish when moist, and by 
the smaller spores. It has been almost always confounded with the fol- 
lowing species, and especially with its var. 8. The apothecia are nume- 
rous, chiefly central, with the margin often flexuose. The spermogones 
are not untrequent, with spermatia equally cylindrical, 0,0045 mm. long, 
scarcely 0,001 mm. thick. It is a variable plant, presenting the varieties 
and subspecies to be described. 
Hab. On the trunks and branches of trees by roadsides, and in avenues 
of lowland and upland tracts.—Disér. Seen only froma very few localities 
in N. England and the Grampians, Scotland ; no doubt overlooked else- 
where.—B. M.: Near Ayton, Cleveland, Yorkshire. Finlarig, Killin, 
Perthshire ; Monaltrie House, Ballater, Aberdeenshire. 
Var. 3. leptalea Nyl. Syn. i. (1860) p. 425.—Thallus narrowly 
laciniate ; laciniz discrete, appressed, fibrilloso-ciliate at the margins, 
the cilia whitish or brownish ; otherwise as in the type.—Cromb. 
Lich. Brit. p. 39; Leight. Lich. Fl. p. 151, ed. 3, p. 140.—Lichen 
leptaleus Ach. Prodr. (1798) p. 108. Borrera hispida Mudd, Man. 
p. 106. Lichenoides hispidum minus et tenerius, scutellis nigris Dill. 
Muse. t. 20. f. 46, a, B, D. 
Differs in the narrower, more discrete, and marginally ciliate lacinia. 
It must not be confounded, as has sometimes been done, with less forni- 
cate states of the following subspecies. The apothecia, which are not 
unfrequent, vary similarly to those of the type. 
Hab. On the trunks of trees, rarely on rocks, in lowland and upland 
districts.—Distr. Occurs only here and there throughout England, in 
N. Wales, S.W. and Central Scotland; rare in Ireland—B. M.: St. 
Leonard’s Forest, Sussex ; Lymington, Hants; Brading, Isle of Wight ; 
Bolt Head, S. Devon; near Penzance, Cornwall ; Oswestry, Shropshire ; 
Aberdovey, Merionethshire; Island of Anglesea; near Gainsford, Dur- 
ham. Near Edinburgh; Appin, Argyleshire; Killin and Blairdrummond, 
Perthshire ; Auchterhouse, Forfarshire; Cults, near Aberdeen. Carri- 
galoe, Cork Harbour. : 
Var. y. subobscura Nyl. Sillsk. F. et Fl. Fenn, Forh. iv. 
(1859) p. 239; Syn. i. p.426.—Thallus greyish or greyish-brown, 
beneath white with scarcely any rhizine; lacinie short, narrow, 
the marginal cilia blackish or dark ; otherwise as in the preceding 
