28. B. trachona Arnold in Flora Ixvii. p. 575 (1884).—
Thallus effuse, thin, subleprose, minutely granulose or nearly
evanescent, whitish, greyish-white or greenish (K —, CaCl — ).
Apothecia minute, plane, opaque, thinly margined, dark-brown, a t
length convex and immarginate ; hypothecium brownish or somewhat
pale ; paraphyses scanty, slightly incrassate a t the apices, not
well discrete ; epithecium nearly colourless or slightly brownish-
black ; spores fusiform-oblong or fusiform, 1-3-septate, 0,011-19
mm. long, 0,0030-35 mm. thick ; hymenial gelatine bluish then
sordid-violet or wine-red with iodine.— Verrucaria trachona Ach.
Meth. Suppl. p. 16 (1803). Lecidea trachona Nyl. in Flora xlvii.
p. 620 (1864) ; Cromb. Lich. Brit. p. 71 ; Leight. Lich. FL p. 329 ;
ed. 3, p. 351.
Exsicc. Larb. Cæsar. n. 80.
In our specimens the thallus is sordid-greenish. Apothecia and
spermogones are frequent ; when the latter only are present the plant
resembles superficially a Verrucaria.
Hah. On granite rocks in maritime localities.—Bistr. Eare in the
Channel Islands and S.W. England.—B. M. The Warren, Noirmont,
Jersey; Dixcart Bay, Sark; near Penzance, Cornwall.
29. B. chlorococca Græwe ex Stenh. in Ofvers. K. Yet. Akad.
Forh. 1862, p. 473.—Thallus thin, furfuraceous or granulose, dull-
yellowish-green. Apothecia reddish-brown or black, minute, adnate,
convex, immarginate ; hypothecium colourless ; paraphyses gelatinous,
distinct, dull-olive-green or pale ; spores fusiform, straight
or curved, 3-7-septate, 0,022-38 mm. long, 0.003-5 mm. thick ;
hymenial gelatine blue then dull-wine-red with iodine.
Var. hilarior Th. Fr. & Huit. Lich. Scand. p. 380 (1874).—
Apothecia reddish or reddish-brown ; paraphyses pale a t the tips,
otherwise as in the type, which has not been found in Britain.
Exsicc. Larb. Lich. Hb. n. 351.
Hab. On trees.—B. M. Charnwood Forest, Leicestershire.
30. B. subturgidula A. L. Sm.^Th a llu s effuse, very thin,
greenish-white or obsolete. Apothecia small, scattered, convex,
immarginate, dark-brown or pale-leaden-coloured; hypothecium
brown, whitish in upper layer ; paraphyses concrete ; epithecium
white or yellowish-white; spores oblong, 0,008-14 mm. long,
0,003-4 mm. thick ; hymenial gelatine bluish then often tawny-
yellow with iodine.—Lecidea subturgidula Nyl. in Flora li. p. 343
(1868); Cromb. in Journ. Bot. vii. p. 48 (1869) & Lich. Brit,
p. 72 ; Leight. Lich. FI. p. 324 ; ed. 3, p. 344.
According to Nylander allied to L. apochrceella, a Finland species,
but differs in the larger spores and the colour of the hj-pothecium.
Hdb. On old stumps of holly.—B. M. Near Lyndhurst, New
- Forest, Hants.
31. B. deducta A. L. Sm.—Thallus effuse, very thin, leprose,
dispersed, greenish ( K - , C aC l- ) , scarcely visible. Apothecia
subminute, blackish, somewhat plane and thinly margined, then
convex and immarginate, reddish in thin section; hypothecium
darker in the middle; paraphyses not discrete ; spores ellipsoid
or oblong, 3-septate, colourless, brownish in the mass, 0,010-13
mm. long, 0,0035-45 mm. th ic k ; hymenial gelatine bluish then
wine-reddish with iodine.—Lec/Jea deducta Nyl. in Flora Iii. p. 410
(1869); Cromb. in Journ. Bot. vii. p. 233 (1869) <fe Lich. Brit,
p. 72; Leight. Lich. PL p. 328; ed. 3, p. 349.
Distinguished from the preceding, to which it is closely related,
chiefly by the colour of the apothecia, but also by that of the
hypothecium and epithecium. The proper thallus, almost always
obscured by a foreign gelatinous thallus, is only very sparingly
present in the specimens gathered.
Hah. On old stumps of holly.—E. M. Near Brockenhurst, New
Forest, Hants.
75. BACIDIA De Not. in Giorn. Bot. Ital. ii. p. 189 (1846)
emend. ; Th. Pries Lich. Arct. p. 179 (1860). Scoliciosporum
Massal. Bic. Lich. p. 104 (1852) ; Mudd Man. p. 185. Eaphio-
spora Massal. Ale. Gen. Lich. p. 11 (1853) ; Mudd Man. p. 186.
(PI. 12.)
Thallus effuse, minutely squamulose or variously crustaceous.
Algal cells Protococcus. Apothecia brightly coloured or dark,
sometimes carbonaceous (Baphiospora), immarginate or with
proper margin only; asci usually 8-spored; spores elongate,
acicular, colourless, pluri-septate, usually straight or sometimes
spirally-curved (Scoliciosporum).
The genus Bacidia, as here understood, includes not only those
forms of LecideacecB with acicular straight spores, but also Scoliciosporum
in which the spores are spirally curved, and Baphiospora
which has been considered by some authors distinct on account of
the carbonaceous outer wall of the apothecium.
1. B. pulvinata Mudd Man. p. 185 (1861).—Thallus indeterminate,
thickish, pulvinate, granulose-squamulose, the squamules
minute, congregate in subconvex tufts, pale-greenish-brown or
cream-coloured (K —, CaCl — ) ; hypotballus thickish, black.
Apothecia small, a t first concave, then plane with thick obtuse
margin, a t length convex and immarginate, black, concolorous
w ith in ; paraphyses slender, conglutinate; epithecium deep-
yellow ; hypothecium thick, dark-reddish-brown (K +blackish) ;
spores acicular or slightly clavate, straight or somewhat curved,
3-7-septate, 0,020-38 mm. long, 0,003-5 mm. th ic k ; hymenial
gelatine, especially the asci, bluish then wine-red with iodine.—
Lecidea pulvinata Tayl. in Mackay FL Hib. ii. p. 123 (1836);
Cromb. Lich. Brit. p. 75 ; Leight. Lich. FI. p. 345 ; ed. 3, p. 372.
Characterized by the peculiar thallus which grows in small
scattered tumid roundish or difform pulvinate masses. The apothecia
are not numerous in the specimens seen, some of the tufts being
entirely barren.