Form 3. c e ra te a Nyl. Lioh. Scand. (1861) p. 73.—ïh a llu s decumbent;
laoiniæ narrow, convex and subcylindrical, acuminate,
subR'labrous.—Cromb. Grevillea, vi. p. 21.— Parmelia furfuracea
ft. ceratea, Aeh. Moth. (1803) p. 255.— B r it. E.vs. : Cromb. n. 139.
Distinguished by the form of tlie more naked laciniæ ; but intermediate
states occur, in which tliese characters are less marked. With us it is
a wavs barren, though Acharius (Licli. Univ. p. 501) says the apothecia
cliielly occur in this form.
Hab. On rocks and old walls in upland districts.—D /str Seen onlv
Irom a ew localities iu S.W., Central, aud N. Knglaud, S. and N.Fl
Scotland, and the S.W. Ilig h lan d s.-D . M. : Hunter Tor, Dartmoor,
Devonshire; Helminton, Cornwall; near Buxton, Derbyshire; Winder-
mere Westmoreland ; Alston, Cumberland. Pentland Hills, near Edinburgh;
Glen halloch, Perthshire; Deerhill AVood, Forfarshire; near
Countesswells, Aberdeen. ’
• p. 153 pro p a rte ; Nyl. Syu.
1. (i»bU) p. 3 /0 .— Ih a llu s fohaooous, horizontally expanded or
ra re ly ascending, variously
lobed aud laciniate ; epi-
thallu s somewhat shining,
beneath usually fibrilloso-
rhizinose ; medullary layer
woolly, composed of filaments
loosely interwoven ;
cortical layer th in , formed
of minute cells with thickened
walls. Apotheoia sc a ttered,
scutelliform, with th a lline
margin ; hypothecium
colourless, theoæ short, the
wall thickened above ; spores
usually 8noe, ellipsoid, simple,
colourless ; hj m enial gelatine
bluish with iodine. Spermogones
generally scattered,
a t length slightly prominent,
blackish ; sterigmata 2- 5-
artioulate; spermatia acioular,
fusiformi-incrassate a t either
apex. Fig. 44.
Parmelia perlata Ach.—a. Fragment-of the
aiihi ti Liieua, xoou. o. xiiree
The species vary iu habit, tbalauiiumand a theca,x350.¿.Three
but are for the most part horizontally
expanded, aud rarely
spores, xGOO. c. Vertical section of the
thallus, with two spermogones, X 30,
d. Sterigmata and spermatia, X500.
e. Three gonidia, X 350.
fruticulose. In no other genus
are the reactions of more value
each'm-her“ ^*'”“ species, which were ofteu not distinguished from
each other, or were regarded merely as varieties, forms, and states.
I t may be divided into the following sections (or suhgenera) and subsections,
according to the presence or absence of rhizinæ aud the colour of
the thallus.
A. K H IZIN OSÆ .—ïh a llu s more or less distinotly fibrilloso-
rhizinose beneath (subgenus Hyporhizia Cromb. Grevillea, xv.
(1887) p. 74).
a. Glaucescentes.— Thallus normally grey, greyish-white or
glaucous.
1. P. p e r la ta Aoh, Moth. (1803) p. 216.—Thallus orbicular or
expanded, imbricato-lobed, smooth, glaucous- or greyish-white ;
beneath somewhat shining, brownish-blaok or blackish, paler a t the
circumference, with sh o rt scattered rhizinæ ; lobes rounded, often
white-sorediate towards th e margins ( K C a C l " ) .
Apothecia moderate or large, scattered, badio-reddisli, th e margin
th in , entire ; spores 0 ,0 1 1 -1 7 mm. long, 0 ,0 0 7 -1 2 mm. thick.—
Gray, Nat. Arr. i. p. 437 ; Hook. Fl. Soot. ii. p. 52 ; Sm. Eng. Fl.
V. qj. 200 ; Tayl. in Alack. El. Hib. ii. p. 148 ; Aludd, Alan. p. 92 ;
Cromb. Lich. Brit. qi. 33 ; Loight. Lich. Fl. p. 128, ed. 3, p. 119.
—Lichen p erlatus Linn. Syst. Nat. ed. 12 (1767) p. 7 1 2 ; Huds.
Fl. Angl. p. 448 ; Lightf. Fl. Scot. ii. p. 839 ; AA’ith . Arr. ed. 3,
iv. p. 68. Lichenoides glaucum gierlatum, suhtus nigrum et cirrliosum
Dill. AIusc. 147, t. 20. f. 39, a , r , u , e .— B r it. Exs. : Leight. n. 76,
302 ; Larb. Lich. Hb. n. 291.
Several species were included under this which have been definitely
separated hy the chemical reactions of the medulla. P. perlata is now
seen to be a much less variable plant than was supposed, though the
thallus varies in the presence or absence of soredia. The apotbecia are
very rare iu this country, nor are the spermogones often seen. WTien
])resent, they are scattered, minute, blackish, rvith spermatia about
0,005-6 mm. long, scarcely 0,001 mm. thick.
Hah. On the trunks of old trees and on rocks in maritime and upland
tracts.—Histr. General and often plentiful in most parts of Great Britain
aud in tlie Channel Islands; apparently rare in Ireland.—B. AI. : Islands
of Jersey, Sark, and Guernsey. St. Leonard’s Forest, near Brighton,
Henfield, and Arundel, Sussex ; Lyndhurst, New Forest, Hants ; Isle of
Wight ; Torquay, South Brent, Ilay Tor, Dartmoor, and Ilfracombe,
Devonsiiire; Bocconoc, near Penzance, aud AA’ithiel, Cornwall; near-
Cheltenham, Gloucestershire ; Twycross, Leicestershire ; Harboro’ Alagna,
AVarwickshire; AVrighton Park, Herefordshire ; Ilaughmond Hill, Shropshire
; Llanhedr, Barmouth, aud Dolgelly, Alerionethshire ; Bousdale
Gill, Cleveland, Yorkshire ; Stavely, Kendal, and Windermere, AA’est-
morelaud. New Galloway, Kirkcudbrightshire ; near Inverary arid Barcaldine,
Argyleshire ; Loch Katrine and Killin, Perthshire ; S. of Fort
William, Lochaber, Inverness-shire ; Applecross, lioss-shire. Near
Cork ; Dunkerron, co. Kerry.
Subsp. P. ciliata. Nyl. Flora, 1878, p. 247.—Thallus moderate
or large, imbricato-loloed, smoothish, often isidiiferous, white or
'f!|
- ' 1.
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