92. PHÆOGRAPHIS AIuell.-Arg. in Plora Ixv.p. 336 (1882).
Hi/menodecton Leiglit. in Ann. Mag. Nat. Hist. ser. 2, xiii. p. 279
(1854). Chiographa Leiglit. /. c. p. 388. (PI. 29.)
Thallus crustaceous, thin, superficial or developed under the
bark (hypophloeodal). Algal cells Trentepohlia. Apothecia [lirellse)
elongate, rarely roundish, immersed then erumpent, simple or
branched ; disc narrow and slit-like or expanded ; proper margins
prominent or disappearing ; hypothecium colourless or dark-
coloured ; asci clavate or elongate, usually 8-spored ; spores
brown, or colourless then brown, elongate, pluriseptate.
Mueller’s arrangement of Graphis and the allied genera has been
followed in order to avoid confusion. Earlier generic names, with
undoubted claims to consideration, have been rejected as being too
vague or too restricted in definition. The two genera Hymenodecton
and Chiographa were iormed by Leighton to mark the difference in
the formation of the outer carbonaceous wall of the apothecium : in '
the former the wall is continuous round the base as a thin dark layer ;
in the latter it is developed only at the sides (dimidiate), and the
colourless hypothecium rests on the substratum. More recently
Crombie and Leighton included all the species under Graphis.
1. Ph. inusta Muell.-Arg. in Flora Ixv. p. 383 (1882).—
Thallus greyish or whitish, thin, membranaceous, smooth or
wrinkled. Apothecia black, immersed, usually rather short and
broad, obtuse a t the ends, simple or branched ; proper margins
very narrow, with a thin thalloid border ; disc plane, naked or
pruinose ; hypothecium colourless ; paraphyses slender, brownish
a t the slightly clavate tip s ; spores elongate-linear, becoming
dark-brown, 5-7-septate, 0,028-38 mm. long, 0,009 mm. thick —
Opegrapha scripta Sm. Engl. Bot. t. 1813 (1807) (non Ach.).
Graphis inusta Ach. Syn. p. 85 (1814) ; Mudd Man. p. 240 (incl.
var. vera) ; Cromb. Lich. Brit. p. 97 ; Leight. Lich. Fl. p. 368 ;
ed. 3, p. 431 (inch f. vera). G. Smithii Leight. in Ann. Mag.
Nat. Hist. set. 2, xiii. p. 278, t. 6, f. 22 (1854) (incl. var. vera).
Exsicc. Larb. Lich. Cæsar. n. 89.
l l typical form described by Acharius (f. vera Leight.) the
thallus is sometimes surrounded by a dark line ; the apothecia are
short and stellately arranged in crowded or scattered groups. I t is
distinguished from other British members of the genus by the
distinctly dimidiate apothecia, the carbonaceous walls being developed
at the sides only.
Hab. On the bark of various trees.—Distr. Rather rare in the
Channel Islands, S. and Central England, and S. and W. Ireland, not
yet recorded from Scotland.—B. M. Beaumont, St. Lawrence, Jersey ;
Withiel, Cornwall; Lustleigh and near Lidford, Devon; Kemble,
Wilts ; near Lyndhurst, New Forest, Hants ; St. Leonard’s Forest
and Hurst, Sussex ; Bpping Forest, Hockley AVoods, Hadleigh AVoods,
and Gosfield Hall, Essex ; Hollybush Hill, Malvern, AVorcestershire ;
Glenbower AVood, Cork ; Clonmel, Tipperary.
Form divaricata A. L. Sm.—Thallus similar to th a t of the
species. Apothecia more elongate and scattered, occasionally
branching a t right angles.—Graphis Smithii vars. elongata and
divaricata Leight. in Ann. & Mag. I. c. p. 279. G. inusta vars.
elongata and divaricata Mudd Man. p. 240 (1861) ; ff. elongata
and divaricata Leight. Lich. Fl. p. 369 ; ed. 3, p. 432.
Differs chiefly in the more elongate apothecia which are often acute
a t the ends.
Hah. On the bark of various trees.—Distr. Rare in S. and E.
England.—B. M. Hurst, Balcombe and Newtimber Downs, Sussex ;
Gosfield Hall and Codham Hall, Booking, Essex.
A^ar. macularis A. L. Sm.—Thallus whitish, usually foi’ming
ra th e r large determinate spots on the bark. Apothecia short,
rarely furcate, straight or curved, densely scattered over the
thallus.—Graphis Smithii vars. macularis and simpliciuscula Leight.
in Ann. & Mag. I. c. p. 279. G. inusta vars. macularis and simpliciuscula
Mudd Man. p. 240 (1861) ; ff. macularis and simpliciuscula
Leight. Lich. Fl. p. 369 ; ed. 3, p. 432.
Exsicc. Larb. Lich. Cæsar. n. 90 ; Leight. n. 285.
Hab. On the bark of various trees.—Distr. More frequent than
the species in the same localities and also in AVales.—B. M. Rozel,
Jersey; Withiel, Cornwall; Torquay, Devon; I. of AVight and Lyndhurst,
New Forest, Hants ; St. Leonard’s Forest and Glynde, Sussex ;
Penshurst, Kent ; Braydon Forest, AVilts ; Epping Forest, Hadleigh
Woods, Codham Hall, Messing, and Barking, Essex; Malvern, AVorcestershire
; Barmouth, Merioneth ; Bettws-y-Coed, Carnarvonshire ;
Glenmire and near Cork ; Killarney, Kerry ; Loughcooter, Galway.
2. Ph. dendritica Muell.-Arg. in Flora Ixv. p. 382 (1882).—
Thallus white or greyish, thin or rather thick, more or less
wrinkled (K + yellow then red). Apothecia somewhat variable,
long or short, acute a t the ends, or almost round, brownish-black,
immersed, scattered, curved or straight and sparingly branched
towards the centre of the thallus, usually branched and radiating
a t the circumference ; disc ra th e r broad and flat, pruinose, with
thin margins, the thallus forming a white pseudomargin; peritheciai
wall continuous as a th in line under the base ; paraphyses
closely conglutinate, inspersed with small granules, slightly
sv'ollen and brown a t the tips ; spores elongate, colourless then
brown, 7-8-septate, 0,042-48 mm. long, 0,009-12 mm. thick.—
Opegrapha dendritica Ach. Meth. p. 31, t. 1, f. 10 (1803); Engl.
Bot. t. 1756 ; Hook, in Sm. Engl. PI. v. p. 147 ; Tayl. in Mackay
Fl. Hib. ii. p. 106. Graphis dendritica Ach. Lich. Hniv. p. 271
(1810). S. P. Gray Nat. Arr. i. p. 503; Mudd Man. p. 241;
Cromb. Lich. Brit. p. 97 ; Leight. Lich. PI. p. 367 ; ed. 3, p. 431
(incl. ff. Smithii and acuta). Hymenodecton dendriticum Leight. in
Ann. Mag. Nat. Hist. ser. 2, xiii. p. 387, t. 7, f. 23 (1854) (incl.
vars. Smithii & acuta).
Exsicc. Larb. Lich. Cæsar. n. 41 ; Carroll Lich. Hib. n. 11.
Well differentiated by the whitish well-developed thallus and the
dendroid branching of the lirellæ. Among the forms distinguished by