466 LICHEN ACEI. [LECANORA. 
A very distinct plant, which when less developed and sterile entirely 
resembles isidioid states of a Pertusaria, in which genus it has been 
placed by Th. M. Fries (Lich. Scand. p. 807) and to which probably it 
really belongs. The peculiar papilla are corallinoid, fragile, more or less 
branched, at first short, then somewhat elongate, often bearing at the 
apices dark brown verrucs, which were mistaken for the fructification by 
some older authors. In our Islands it is rarely well fertile. The spermo- 
gones, however, are not unfrequent, with spermatia (fide Nyl.) 0,0035 
mm. long, 0,0005 mm. thick. 
Hab. On mosses upon the ground, rarely on schistose rocks in alpine 
situations.—Distr. Local and scarce towards the summits of a few of the 
higher mts. of the S. and N. Grampians, Scotland—B. M.: Craig 
Calliach and Ben Lawers, Perthshire; Cairngorm and Cairntoul, 
Braemar, Aberdeenshire. 
Form depressa Cromb.—Thallus epapillate, greyish-white. 
Apothecia minute, adnate, numerous and crowded. 
Perhaps only a stunted condition depending on situation, as a few very 
short, simple papillee are here and there visible. 
Hab. On the bare ground in an alpine locality Distr. Very sparingly 
on one of the N. Grampians, Scotland.— B. M.: Summit of Ben-naboord, 
Braemar, Aberdeenshire. 
163. L. cinerea Somm. Suppl. Fl. Lapp. (1826) p. 99; Nyl. Not. 
Sallsk. pro F. et Fl. Fenn. Forh. n. ser. v. (1866) p, 136.—Thallus 
determinate or subeffuse, rimoso-areolate or diffracto-areolate, grey 
or greyish-white (K+ yellow, then rusty-red, CaCl—, medulla 
I—); hypothallus black. Apothecia small or submoderate, im- 
mersed and concave, at length sessile and plane, black, naked; the 
thalline margin entire, subpersistent; spores Sn (rarely 6ne), 
subellipsoid, 0,015-23 mm. long, 0,008-14 mm. thick ; paraphyses 
not discrete; hymenial gelatine bluish, then tawny or wine-red 
with iodine.—Cromb. Lich. Brit. p. 54; Leight. Lich. Fl. 
p. 195, ed. 3, p. 172.—Aspicilia cinerea Mudd, Man. p. 162 pro 
parte. Urceolaria cinerea Sm. Eng. Fl. v. p. 172; Tayl. in Mack. 
Fl. Hib. ii. p. 132; Gray, Nat. Arr. i. p. 458. Lichen cinereus 
Ach. Prodr. (1798) p. 32; Eng. Bot. t. 1751.—As observed by 
Acharius 1, ¢, this is scarcely Lichen cinereus Linn. Mant. i. (1767) 
p- 132, of which there is no specimen in his Herbarium ; nor is it 
Lichen cinereus Huds. Fl. Angl. ed. 2, p. 525. 
A good species, though often not well characterized nor rightly 
limited. In this latter respect various others have been subsumed under 
‘it which are now readily separated, apart from the other distinctive 
characters, by their negative reactions with K. It is thus a much less 
variable plant than was supposed, and is not so apt to be confused with 
some of itsallies, The thallus,which is generally well fertile, occasionally 
spreads extensively, but is usually limited by the hypothallus. A state 
very rarely occurs in Britain on nehistons rocks (Tremadoc, N. Wales, fide 
Leighton) in which the thallus is greyish-ochreous, when it is form 
ochracea Leight. Lich. Fl. ed. 8, p. 193 (Urceolaria cinerea y. ochracea 
Schaer. Spicil. p. 72). The spermogones are frequent, with spermatia 
0,016-21 mm. long, scarcely 0,001 mm. thick. 
