026 
P A R M 
agrees in habit, and with Tome of them very ftrikingly 
in the character and fituation of its feeds. Indeed it 
muft include the whole of the Lichens, though under a 
different arrangement, the name of Lichen, as a generic 
term, being abolifhed. See that article. 
The genus Parmelia fwallows up the greater part of 
this natural order : 204. fpecies are defined in the Metho¬ 
ds s, befides feveral in the Supplementum, of Acharius. 
This author is often in doubt to which genus fome fpe¬ 
cies belong, for want of knowing them in every ftate of 
growth. The true Parmelia have an aceffory border 
of the colour and fubftance of the cruft, but no proper 
border formed of the fubftance of the dilk. The generic 
effential characters Ihould therefore ftand as follows: 
“ Shields orbicular, horizontal, fuperficial, fomewhat 
elevated, with a cartilaginous accefibry border.” 
The dijk is fometimes concave, oftener nearly flat, or 
indeed convex and hemifpherical when far advanced in 
age, of a different fubftance and colour from the border, 
and without any border, or feparate edge, of its own 
fubftance. The texture of the dilk is tolerably firm, though 
occupied with innumerable vertical parallel cells, each 
containing about eight minute feeds, placed one above 
the other. Its external colour is different in different 
fpecies, molt generally brown or reddilh, but always to¬ 
tally unlike that of the border ; internally it is paler. 
By age the dilk in many fpecies becomes loofened, falling 
out, and leaving its border in the fliape of a fmall cup, 
or rather faucer. 
The border is of the fame colour and fubftance with the 
frond from which it proceeds, being elevated more or 
lefs above the level of that part, and very generally, at 
leaft in the more leafy fpecies, attached merely by a cen¬ 
tral ftalk, though its circumference is flat, and clapped, 
often very clofely, to the furface. In the cruftaceous 
kinds the union of the parts is more confiderable ; in the 
more filamentous or branched ones it is merely central, 
by an elongated and obvious ftalk. -The extreme part of 
the border is more or lefs tumid and thick, either fmooth 
or powdery, entire or crenate, rarely fringed or leafy, 
while the very edge itfelf is inflexed and even. 
Th e frond is various, and of many different fliapes and 
appearances. When cruftaceous, leprous, or tartareous, 
it is either uniform, and limited by a well-marked border, 
4 ufually blackifli ; or it is loofely difperfed, without any 
diftinCt limitation, frequently in fmall portions or patches, 
and then, in many inftances, finally difappears by age, 
leaving the bare and fcattered ftrields, as if growing in¬ 
dependently out of the ftone or bark. In other cafes 
the frond confifts of lobed fragments, afl'uming a leafy 
imbricated afpeCt, and a cartilaginous texture; from 
which there is an infenfible gradation to a truly leafy 
configuration, which is either membranous or coriaceous 
dilated and lobed, or narrow and repeatedly branched, 
round or compreffed, ereCt, horizontal, or pendulous : 
in all cafes it readily imbibes moifture, and by that 
means becomes inftantly foft, flexible, and vegetative, 
however dry, contracted, and brittle, before. The colour 
of the frond is commonly very different in its moift 
and flourifliing ftate to what it is when dry; being, 
in the latter condition, ufually pale and greyifli, but 
afl'uming a beautiful green when moiftened. Yet there 
are fome fpecies always of the fame grey hue, whether 
wet or dry, which by that very circumftance are well 
diftinguiftied from others. 
The male fructification of Parmelia is fuppofed, rather 
than known, to confift of fcattered powdery warts, moftly 
of a lighter colour than the frond, on whofe furface or 
fegments they are fituated, burfting, as it were, from 
under the cuticle. There is perhaps much reafon to fup- 
pofe fuch efflorefcences to be of the nature of buds, or 
gemma, by which the fpecies may be increafed. The 
great Hedwig however fpeaks of them as clearly anthers. 
They are by far molt abundant when the fliields, which 
are unqueftionably the female parts of fructification, are 
ELIA. 
fparingly produced ; which is rather in favour of their 
being buds. But the parts of the fliield, at the period 
when impregnation, in whatever mode, muft take place, 
are fo minute, homogeneous, and obfcure, that, if we ftill 
remain in total ignorance of the flowers of ferns, no won¬ 
der we are equally in the dark refpeCting lichens. 
To enumerate the fpecies of Acharius or of Kedwig 
would be, as already noticed, only to repeat our article 
Lichen under a new arrangement. We fhall therefore 
fufficiently elucidate this genus by a defcription and 
figures of four entirely-new fpecies communicated to the 
Linnsean Society by Dawfon Turner, efq. F. R. S. in the 
year 1806. 
1. Parmelia velata, or veiled Parmelia: cruft diftinCt, 
wartiftily membranaceous, wrinkled, and whitiffi; Ihields 
fmall and cluftered ; dilk flat, of a whitifh hue, and veiled 
or enwrapped in an albefcent membrane. The alga, or 
frond, is arboraceous, irregularly orbicular. The dia¬ 
meter from two to fix inches. The cruft is limited with¬ 
in an uncommon fort of zone, very thin, fmooth, in 
adult fubjeCts ; thicker towards the centre. The fliields 
are fo numerous as often to fill up the whole furface of 
the cruft; conglomerated, hardly bigger than poppy- 
feed, but often of an angular fhape, owing to mutual 
prefiure; the margin of the fame colour with the cruft, 
thicker, and little if at all elevated. The dilk is always 
flat; the membrane very thin, of the fame fubftance with 
the margin, and as if originating from it; the iniide of 
a beautiful fawn-tint. Found on alh-trees in Suffex; but 
rare. This fpecies is exhibited on the annexed Plate, of 
the natural fize, at fig. 1. magnified at fig. 2. a feCtion at 
fig- 3 - 
2. Parmelia carneo-lutea, or pale flefli-coloured parme¬ 
lia : cruft membranaceous, very thin, white ; Ihields flat, 
yellow', and in young fubjeCts involved in a lacerated mar¬ 
gin. The frond is arborefcent, cruftaceous, largely and 
indeterminately dift’ufed. 
The cruft of this lichen is fo exceedingly thin, that 
its appearance at firft light is nothing more than that of 
an unufually bare and fmooth part of the tree -. nor can 
its fructification be difcovered udthout attentive exami¬ 
nation ; for even the fliields are by no means of a nature, 
either from their colour or fize, to (trike a curfory obfer- 
ver. Mr. Borrer therefore fufpeCts, and, as it feems, 
not without reafon, that the grey tinge frequently obfer- 
vable on the bark of old elms belongs in reality to this 
plant. The nature of the fliields is fo peculiar, that a 
few remarks with refpeCl to thefe is all that it can be ne- 
ceffary to fay for the purpofe of effectually difcriminating 
this lichen from its congeners. They are very different 
from thofe of any other Parmelia, and more refemble the 
apothecia of Urceolaria exanthematica, being almoft wholly 
immerfed in the cruft, and in their firft ftage enveloped 
by the margin, which foon fplits into different fegments, 
though not with the regularity obfervable in that plant, 
difclofing the flat yellowilh or flefli-coloured dilk. In 
the older fliields the margin becomes worn down, fo as 
to be level with the dilk, and is in this ftate thick, obtufe, 
uneven, and crenulated ; it is alfo fometimes quite obli¬ 
terated. Found on the bark of old elms about Lewes, 
Albourne, Steyning, Southwick, and Haftings, in Suffex. 
Some of this is fliown, of the natural fize, on a piece of 
wood, at fig. 4- and magnified at fig. 5. 
3. Parmelia Clementi: ftalk membranaceous and crufty, 
orbicular, whififh, with a lobated margin ; the lobes di¬ 
lated, fliort, multifid ; fliields of a dark livid tint, the 
margin white. The frond is arborefcent, two inches in 
diameter, the ftalk adhering fall to the tree, undivided 
towards the centre, ftrewed over with white dull; the 
envelope leafy; the lobes flat, dilated, imbricated, and 
wrinkled; always white on both fides, whether wet or 
dry. The fliields are by no means numerous ; they arife 
from the middle of the thallus, or ftalk ; orbicular, firft 
concave, with a half-clofed margin ; afterwards open, 
and flattilh. The dilk, when wet, is of a black-livid tint, 
and 
