buellia] lecideack.*: 181 



situations. — Distr. Very local and scarce on summits of a few of the 

 Grampians, Scotland. ^ — B. M. Mael Graedha, Killin, Perthshire ; 

 Morrone, Braemar, Aberdeenshire ; Ben Nevis, Invernessshire. 



31. B. pulchella Tuckerm. Gen. Lich. p. 185 (1872).— 

 Thallus orbicular, thick, wrinkled, roundly lobed at the cir- 

 cumference, citrine-sulphureous or bright-greenish-yellow (K — , 

 CaCl — , medulla I — ) ; hypothallus black. Apothecia moderate, 

 appressed, plane, obtusely margined, at length sessile, convex, 

 immarginate, black, concolorous within; hypothecium thick, black; 

 paraphyses coherent, yellowish-brown or sordid-greenish, dark- 

 brown at the apices ; spores ellipsoid, obtuse at the apices, 

 often slightly constricted in the middle, brown, 0,010-17 mm. 

 long, 0,007-0,010 mm. thick ; hymenial gelatine bluish with 

 iodine. — Lichen pidchellus Schrad. in Schrad. Journ. Bot. i. 74 

 (1801). L. galhiilus Ramond ex DC. Fl. Fr. ii. p. 368 (1805). 

 Lecidea pulchella Scha^r. Enum. p. 100 (1850); Leight. Lich. 

 Fl. ed. 3, p. 544. L. galhula Nyl. in Act. Soc. Linn. Bord. 

 ser. 3, i. p. 388 (1856); Cromb. Lich. Brit. p. 93. 



Well characterized not only by the form of the thallus, but also 

 by its colour, which readily attracts the eye. In age, according to 

 Th. Fries (Lich. Scand. p. 588), the thallus becomes pulverulent 

 or rimulose. The apothecia are here and there confluent. 



Hab. Incrusting decayed mosses on the ground in crevices of 

 boulders in alpine localities. — Distr. Extremely local and scarce on 

 one of the N.W. Grampians, Scotland. 



32. B. colludens Tuckerm. Syn. N. Amer. Lich. pt. 2, p. 100 

 (1888). — Thallus effuse or subdeterminate, areolate, the areolae 

 plane or somewhat convex, scattered or contiguous, greyish-red 

 or brownish-grey, sometimes almost obsolete (K — , CaCl — , I — ) ; 

 hypothallus black. Apothecia rather large, sessile or innate- 

 sessile, plane, black, the margin thickish, entire, or rarely crenu- 

 late ; hypothecium brownish-black ; paraphyses conglutinate, 

 brownish-black at the clavate apices ; spores at first colourless 

 then brown, ellipsoid or somewhat fusiform, with a hyaline 

 epispore, 0,018-29 mm. long, 0,007-14 mm. thick ; hymenial 

 gelatine deep-blue with iodine. — Lecidea colludens Nyl. in 

 Flora liii. p. 38 (1870) ; Cromb. in Journ. Bot. viii. p. 99 (1870) ; 

 Leight. Lich. Fl. p. 314. L. atroalha var. applanata Fr. Summa, 

 p. 116 (1846). L. applanata Leight. Lich. Fl. ed. 3, p. 327 

 (1879) (non Chev.). 



Exsicc. Larb. Lich. Hb. n. 355 ; Johns, n. 391. 



The thallus varies in thickness and colour, and is sometimes 

 limited by the hypothallus. The apothecia are numerous, scattered or 

 contiguous, and sometimes slightly umhonate, with the margin usually 

 persistent, thoi.gh occasionally they are convex and immarginate. 



Hah. On schistose and quartzose rocks, usually by streams in 

 upland and subalpine districts, — Disfr, Bather local in Central 



