1
Fig. 6.
VUrygium. omtHfngum N y l . - a . Longitudinal section of *aUus X 27.ffi
6. Transverse section of the same. c. Vertical section of a speimogono,
X42. d. Jointed sterigmata.
This genus is analogous to Panmdaria among the Echenacm, from
which, however, it is distinguished hy the iffisence of a, hypothallus. In
this country few species have occurred, hut prohahly others will be
detected.
1 P. c e n trifllg um Nyl. Bull. Soc. Bot. i. (1 8 5 4 ) p. 8 2 8 ; Syn.
i. p. 92 t. ii. ff. 1 1 -1 5 .—ThaUus smaU, laciniato-radiate, c e n tn tu -
gal dark- or ohestnut-hrown, often blackish in th e centre ; laciniffi
divaricato-multifid, plane or somewhat convex, narrow, crowded,
very th in ly longitudinaUy rugulose. Apothecia unknown.
Externally this looks like a small near to dark vars. of PA.
ohscura; hut its anatomical structure is essentially different. The thallus
is only about J inch in diameter (even smaller in the only Bntish specimen
seen), and is more or less centrifugal. The ^
greenish, often moniliform towards the upper surface. No apothecia
L v e yet been detected, hut the spermogones (not present in our specimen)
are known; they are tuberculose, usiiaUy blackish above, with
multi-articulate sterigmata; spermatia straight, slightly acute at the
apices, 0,005-0,006 mm. long, 0,001 mm. thick.
Hab. On calcareous rocks in a suhalpine hilly district.—Disfr. Extremely
local and scarce, having been found only very sparingly m S.W. England.
—B. M .: Cheddar Cliffs, Somersetshire.
2. P . p a n n a rie llum Nyl. Siillsk. pro F . e t F l. Not. iv. (1859)
p. 236 ; Flora, 1869, ]). 4 1 .—Thallus moderate, hicimato-riidiaie
a t th e circumference, subcoralloideo-multifld or microphvlline and
usually diffraoto-globulose in the centre, dark-oUve or olive-hrownish-
black, opaque ; laoiniie th in , plane, multifid, imbricately crowded,
ohsoletely rugulose. Apothecia small, plane or slightly convex,
b la c k ; spores ellipsoid, 3-septato, 0 ,0 1 5 -2 0 mm. long, 0 ,0 0 6 -8 mm.
th ic k ; hymenial gelatine deep blue with iodine.—Cromb. Grevillea,
V. p . 1 0 8 ; Leight. Lich. F l. ed. 3, p. 12.
This is externally somewhat like Pannaria trisqitata Nyl., hut differs
in the absence of a hypothallus, and in the laciniie being radiate a t the
circumference and usually digitate at the apices; the spores also are
somewhat smaller. In the only fertile British specimen seen the apo-
tliecia are sparingly present.
Hab. On schistose rocks in alpine situations.—Distr. Very local and
scarce amongst the S. Grampians, Scotland.—B. M. : Summit of Craig
Calliach, Perthshire.
3. P. Lismorense Cromb. Grevillea, v. (1877) p. 108.—Thallus
th in , subfurfuraoeous, th in ly or ohsoletely radiate, adnate, variously
confluent, blackish or olive-black. Apothecia small, th in ly m argined,
black, dark w ith in ; sporos oviform, 1 -septate, 0,010- 0,011
mm. long, 0 ,0 0 5 -0 ,0 0 6 mm. th ick ; epithooium bluish-black ; hypo-
theoium cellular, and (with th e peri thecium) violet-blackish; hymenial
gelatine bluish, th en dark-yellowish w ith iodine.—Nyl. Flora,
1877, p. 2 2 1 ; Leight. Lioh. Fl. ed. 3, p. 12.—B r it. Ex.s-. Cromb.
n. 101.
The thallus spreads rather extensively, though not continuously, over
the substratum. In its younger state the radii are more discrete at the
circumference. I t is allied to P. asperellum Nyl., from which it differs
in the thallus and the smaller spores.
Hab. On calcareous rocks in maritime tracts.—Distr. Local and scarce
in the S.W. Highlands.—B. M .: Island of Lismore, Argyleshire.
11. LEPTOGIDIUM
Nyl. Flora, 1873, p. 195
{cfr. Cromb. Grevillea, v.
p. 76).—Thallus minute,
fruticulose, branched,
somewhat fragile ; gonimia
moniliform ; cortical
layer cellular, distinct.
Apotheoia subbiatorine ;
spores 8nse, eUipsoid,
simple, colourless ; hymenial
gelatine bluish w ith
iodine. Spermogones not
seen rightly developed.
This genus, recently instituted
by Nylander, is
Fig. 7. a
Leptogidium dmdriscum Nyl. — a. Thalline
branch and branehlet, X 30. h. Transverse
section of a branch, X 200. c. Apex of a
bifurcate branehlet, showing the moniliform
chains of the gonimia, X 200. d. Two
series of gonimia, x 350.
¡' III'!
I ' I '