PARMELLA. | PARMELIE1, 255 
Var. 3. letevirens Nyl. Bull. Soc. Linn. Normand. vi. 1872, 
p- 272.—Thallus orbicular or effuse, greenish-olive or greenish- 
brown, more or less covered with concolorous isidia (medulla CaCl+ 
red). Apothecia and spores as in the type.—Cromb. Grevilica, x. 
p-. 26.—Imbricaria olivacea y. letevirens Flot. Lich. Sil. (1829) 
n.90. Parmelia fuliginosa f. olivacea Leight. Lich. Fl. ed. 3, p. 123. 
Purmelia Borreri f. olivacea Leight. Lich. Fl. ed. 2, p. 479. 
Though differing in the colour of the thallus and of the isidia, the 
reaction of the medulla shows that this is only a variety of P. fuliginosa. 
States occur in which there is scarcely any trace of isidia (form denudata 
Cromb., probably referable to subsp. g/abratula Lamy, as in Greyvillea, xv. 
p. 75). In herbaria specimens the isidia often become abraded, rendering 
the thallus white-punctate. The apothecia are not uncommon, but the 
spermogones are rarely seen. 
Hab. On old trees and pales, rarely on walls, in maritime and upland 
districts.—Distv. Local and scarce in E. and N. England, N. Wales, the 
Tlighlands, Scotland, and N.W. Ireland—B. M.: Hopton, Suffolk ; 
Bettws-y-Coed, Denbighshire ; near Dolgelly and Rhewgreidden, Merio- 
nethshire; Devil’s Bridge, Cardiganshire; Kendal and Levens Park, 
Westmoreland ; Keswick, Cumberland. Appin and head of Loch Awee, 
Argyleshire; Loch Ard and Glen Lochay, Perthshire; Durris, Kincar- 
dineshire ; Morrone, Braemar, Aberdeenshire. Dertyclare and near Kyle- 
nore, co. Galway. 
26. P. stygia Ach. Meth. (1803) p. 203.—Thallus orbicular, 
appressed, somewhat shining, smooth, imbricate, olive-brown or 
blackish ; beneath pitch-black, paler at the margins, with but few 
rhizine ; lacinize sublinear, palmato-multifid, convex, incurved at the 
apices (K_,CaCl_). Apothecia moderate or somewhat large, sub- 
concolorous, the margin granulato-crenate; spores 0,008-10 mm. 
long, 0,006-7 mm. thick.—Gray, Nat. Arr. i. p. 441; Hook. Fl. 
Scot. ii. p. 54; Sm. Eng. Fl. v. p. 202; Mudd, Man. p. 100; Cromb. 
Lich. Brit. p. 35; Leight. Lich. Fl. p. 124, ed. 3, p. 116.— 
Lichen stygius Linn. Sp. Pl. (1753) p. 1143; Dicks. Crypt. fase. iii. 
p- 16; With. Arr. ed. 3, iv. p. 30; Eng. Bot. t. 2048.—Brit. Hus. : 
Dicks. Hort. Sic. n. 25 pro parte. 
Somewhat resembles Platysma Fahlunense, but distinguished by the 
form of the Jacinise, the character of the spermogones, and the absence of 
medullary reaction with K. It is generally fertile, though the apothecia 
are rather scattered and not numerous. The spermogones, which are 
frequent, are immersed, with spermatia 0,005 mm. long, 0,001 mm. thick, 
constricted in the middle and somewhat obtuse at the apices. 
Hab. On rocks and boulders, granitic and quartzose, in subalpine and 
alpine regions.—Disir. Local and rare, being confined to a few of the 
higher Grampians, Scotland.—B. M.: Ben More, Perthshire ; Lochnagar, 
Ben-naboord and Ben Macdhui, Braemar, Aberdeenshire ; Ben Nevis, In- 
verness-shire. 
27. P. alpicola Fr. fil. Nov. Ac. Reg. Soc. Sc. Upsal. (1861) 
p- 157.—Thallus orbicular or expanded, somewhat appressed and 
adnate, subopaque, blackish-olive or dark-grey ; bencath very black, 
