over the smooth surface of the substratum, outdistancing the thalline
areolæ. It predominates also in f. coracinum (Flot. I. c.) where the
areolæ are dark and diffuse, in f. dispersiini Leight. where they are light
coloured and scattered, and in f. fuscescens Leight. where the areolæ
are also light in colour but contiguous and very thin.
Hab. On hard rocks, granitic, schistose, or siliceous.—Distr.
General and common throughout the British Isles.—B. M. St. Boniface
Down, Ventnor, I. of Wight ; Lyndhurst, Hants ; Beeding
Downs, Stanmer Park and Hastings, Sussex ; Shiere, Surrey ; Highbeach,
Epping Forest, Essex ; Bosbury Ring and Caer Caradoc,
Shropshire ; Middletown Hill, Montgomeryshire ; Barmouth and
Dolgelly, Merioneth; Thetford Warren, Norfolk; Cliffrigg, Lounsdale
and Ayton, Cleveland, Yorkshire ; Portlethen, Kincardineshire ;
Ben Lawers, Perthshire; Morrone, Braemar, Aberdeenshire; Cork;
Killree, Clare ; Howth, Dublin.
11. Rh. postumum Th. Fr. Lich. Scand. p. 634 (1874).—
Thallus effuse, thin, subgranulose, scattered or evanescent,
greyish (K —, CaCl — , medulla I — ). Apothecia subminute,
somewhat plane and thinly margined, a t length convex and
immarginate, black, paraphyses concrete ; epithecium and hypothecium
brownish ; spores (6-) 8 in the ascus, ellipsoid-oblong,
3-septate, usually with a few oblique or longitudinal septa,
colourless or a t length brownish, scarcely halonate, 0,015-16 mm.
long, 0,006-7 mm. thick, or shorter and rather thicker ; hymenial
gelatine bluish, the asci wine-red with iodine.—Lecidea postuma
Nyl. in Flora li. ji. 345 (1868) ; Cromb. in Journ. Bot. vii. p. 50
(1869) & Lich. Brit. p. 87 ; Leight. Lich. FI. p. 328, ed. 3, p. 349.
A rather obscure plant, related to Bh. confervoides, of which
Nylander says it would almost appear to be a starved condition, with
smaller spores. In the two specimens gathered the thallus is scarcely
visible, except around the somewhat scattered apothecia.
Hab. On calcareous stones among detritus in an alpine situation.—
B. M. Ben Lawers, Perthshire.
12. Rh. distinctum Th. Fr. Op. cit. p. 625.—Thallus greyish
or brownish, m inutely areolate, the areolæ plane or slightly convex
(K —or slightly brownish, GaCl — ) ; hypothallns black. Apothecia
ra th e r small, depressed, plane, thinly margined or immarginate ;
hypothecium purplish-brown ; paraphyses slender, involved in
mucus, purplish-brown a t the tips ; spores oblong, ellipsoid, or
irregular in form, colourless, becoming pale-olive, 1-5-septate and
muriform, halonate, 0,024-32 mm, long, 0,012-15 mm. th ick ;
hymenial gelatine deep-blue with iodine.
Differs from Bh. confervoides in the purple colour of hypotheoimn
and epithecium.
Hab. On granitic or sandstone rocks, rare.—B. M. Morrone,
Braemar, Aberdeenshire.
13. Rh. Ohscuratum Massal. Bic. Lich. p. 103 (1852).—
Thallus greyish- or pale-brown, thin, minutely areolate, the
areolæ contiguous or dispersed, nearly plane, sometimes evanescent
(K+pale-yellow, C a C l - ) ; hypotballus black, often obsolete.
Apothecia black, varying in size, plane, innate-sessile or
adnate with an obtuse, thick margin, which rarely almost dis-
appears ; hypothecium brownish - black ; paraphyses slender,
coherent, dark-brown towards the apices ; spores oblong-ellipsoid,
colourless, becoming brownish, muriform, halonate, 0,024-50 mm.
long 0,012-18 mm. thick ; hymenial gelatine deep-blue with iodine.
— Bh. petræum var. lavatum Mudd Man. p. 220 (1861). Lecidea
petræa var. ohscurata Ach. Lich. Univ. p. 156 (1810); f. lavata
Cromb. Lich. Brit. p. 86 (1870). L. ohscurata Schær. Spicil
p. 130 (1828); Leight. Lich. FI. ed. 3, p. 377. L. atroalba
yar. concreta Wahlenb. FI. Lapp. p. 471 (1812). L. concreta
Leight. Lich. FI. p . 351 (1871). L. lavata Nyl. in Flora Ivi.
p. 23 (1873); Cromb. in Journ. Bot. xi. p. 135 (1873) ; Leight
Lich. FI. ed. 3, p. 378. v / ^ s
The thallus is occasionally shining and almost copper-brown or
née?!!“® (f- ferrata Nyl. Lioh. Scand. p . 234
(ibbl) ). ihe^ apothecia vary in size, but are usually rather large,
strongly marginate, and occasionally also umbonate. When growing
(T Za!ato) be submerged, the thallus almost disappears
Hab. On rocks.—Distr. Somewhat rare in upland or subalpine
D. M. Pulborough, Sussex; Llandj^ssil, Cardiganshire;
Aberdovey, Merioneth ; Nant Francon and Trefriw Falls, Carnarvon-
shire; Caradoc, Shropshire; near Thirsk, Yorkshire; Portlethen,
Kmcardmeshire; Barcaldine, Argyll; Stirlingshire; Ben Lawers,
Perthshire (f. ferrata) ; Glen Callater, Braemar, Aberdeenshire ; Ben
JNevis, Invernessshire; Applecross, Rossshire; Killarney, Kerry.
14. Rh. plicatilis A. L. Sm.—Thallus dirty-white, minutely
plicate or warted, cracked-areolate (K+yellow, CaCl+yellow) ;
hypotballus brown. Apothecia blackish-brown, large, closely
adnate, sometimes connate, the margin obtuse, undulate, becoming
attenuate and obliterated in age ; hypotheoium thick, blackish-
brown paraphyses stoutish, subdiscrete, yellowish-brown a t the
tips ; spores 4-8 in the ascus, elongate-ellipsoid, muriform, colourless,
becoming faintly brownish, halonate, 0,027-30 mm. long,
0,009-10 mm. th ic k ; hymenial gelatine deep-blue with iodine.—
Bh. eoniopsoideum Hepp ex Arnold in Flora Ixvii. p . 593 (1884)
(fide Arnold). Lecidea plicatilis Leight. in Ann. Mag. Na t
Hist. ser. 4, iv. p. 201 (1869) & Lich. FI. p. 351 ; ed. 3, p. 380 ;
Cromb. in Journ. Bot. viii. p . 98 (1870). L. coniopsoidea Hue
in Bull. Soc. Linn. Norm. sér. 4, viii. p. 314 (1894).
Hue I. 0. notes that in some specimens the thallus changes from
yellow to red on the application of potash.
Hab. On alpine rooks.—A, M. Llyn-y-Cae, Cader Idris, Merioneth.
15. Rh. geminatum Koerb. Syst. Lich. Germ. p. 259 (1855),
emend. Th. Fr. Lich. Scand. p. 623 (1 8 7 4 ) .-Thallus subeffuse,
warted-areolate, the areolæ contiguous or somewhat scattered,