93 
leaf-like ; the inner one, called the 
corolla, more conspicuous and variously 
coloured. It is the perianth, and espe- 
cially the coroll.a, as the most showy 
part, that is g'eucrally called the flower 
in popular language. In very many 
cases, a so-called simple perianth (of 
whicli the parts are usually called leaves 
or se!jmt7',ts) is one in which the sepals 
and petals are similar in form and 
texture, and present apparently a single 
whorl. Ihit if examined in the bud, 
one-half of the parts will generally be 
found to be placed outside the ot})er 
half, and there will frequently be some 
slight difference in texture, si/'e, and 
colour, indicating to the close observer 
the presence of both calyx and corolla. 
Hence much dijicrepancy in descriptive 
works. Where one botanist deseribes 
a .simple perianth of six s-'gments, 
another will speak of a double perianth 
of three sepals and three petals. The 
term “perianth” should only be em- 
ployed to designate a (jalyx and corolla 
the liniits of which arc undeflned, so 
that they cannot bo satisfactorily dis- 
tingaislicd from eaclj other, as in the 
case td Tulips, Lilies, Crinums, and 
Orohicts. But even in thoRC examples 
the limit bdween calyx and corolla 
not only exi-ts, liufc is often ]»Iainly 
evifUiiit. 
pER'iCAfiF, Pericar'pium— T he portion of 
thf? fruit forTa^’il of the ovary, and 
whatever adheres to it, cxchisive of 
and outside of the seed or seeds, ex- 
clusive also of the jiersistent I’eceptacle, 
or of whatever portion of the calyx per- 
sists round the ov.ary witliout adhering 
to lb. Pkuicli'niit.u— T oe involacrmn 
of Comp</sjt{B. 
Perich-k'tial Le.U'es— T hose at the base 
of the fruit-stalk of a djoss. 
Per'iderm, Peridermiu — The enclosing 
nfiernbrane. 
Perid'ium — G oTieral term for the outer 
env'elo]nng coat of a sporo]dioro uijon 
which the spores develop in a closed 
cavity. Ju Uredmcje it envelopes the 
secidium, and is also tenuod pseiuiO’ 
peridiuhi, pai'aphyscs eiirelopr.. In Gas- 
troiuycetes, termed also utcrusy and 
may be dilferentiatod into pti'klium 
* externum (outer peridinm), the outer- 
most layer which opens in various ways 
and sei)arates from the perkU-um 
inlernvvL (inner pevidium), s, layer 
directly enclosing the gleha. 
Perien'ciiyma — I rregular celluhar tissue, 
chii'dy in glands and spheroidal 
masses, 
Pertgy'noub (/.r., round the ovary) — The 
term is applied to iiotals, &:c., when the 
disk baai'ing them is quite free from the 
ovary; hut is more or less combined 
with the base of the calyx -tube. The 
ovary is then still described as frreov 
superior^ even though the combined 
disk and calyx-tube may foim a deep 
cup with the ovary I 3 ing at tho bottom ; 
the calyx is said to he free or inferior y 
and the petals are def^cribed as 
imerted on (he calyx. 
Perifhkr'al. — The outer [fortion of a 
circle. 
PerTsPERM, PERIHPEU'iMUTJI, PERlfsrER'MVM 
— Synojiym for “Albunun.” 
Per'estomb — T heopeningof the s^iorangium 
of mosses after the removal of the 
calyptra and operculum. 
Perithe'cia, — T he cysts or capsules con- 
taining the asci. 
Pekuihk'cipm — T he emelnijo .surrounding 
the masses of fructifie.ation in Pnngi and 
Lichens. 
PerTtkoral, FerTfropus— W here the axis 
of IX seed is ]>evpcmliculav to the axis of 
the pericarp, to which it is attached. 
PEitLA'Riu.s, PERLA'Trs— Shining with a 
pearly lu>tro ; funiishcd with rounded 
tubercular appendages. 
pERprisii/Lr.s— Synonym for “Fusiilus.” 
Peksj.st'ext- -When any part or organ, in 
particular plants, I'cmains boyt.nd the 
peibjd r>f mnlurity and fall, appointed 
for .similar parts in other plants ; or to 
the perioil of full maturity uttuiued by 
neighbouring parts. 
Per'sonate, J’ersoxa'tcs— a form of 
iTionopctalous bilabiate corolla, where 
the orifice (^f tlie ttibe is c](r-.ed by an 
iiifiated [m-jection of the throat. 
PjiRTu'strs — Hynonym for “ I’erforatu.s.” 
(See the outer gluuje of Audropogon 
pevtu»as.) 
PER'vioua, PEiivrrs— Admitting tho pas- 
sage r.f some portion without: intoiTup- 
tiun ; as wiiere the pith is continued 
through a node in tlio stem. 
Per'ula— L ittle pr>uch. A sac formed in 
some Orchids by the prolonged and 
united ba.se.s of two of the .segments of 
their perianth. The cuji like covering 
of buds, formed by tho abortion of their 
outer leavo.s. 
Pes— A foot, or, as in Tpomo^a Pes-caprm, 
from the supposed reseniblanco of tlte 
leaves to the foot of a goat. 
Pet'al, Pf/tai.um — O ne of the foliaceous 
expansions coristituting tho subordinate 
parts of the floral wh<irl, termed the 
corolla. They aro mmdly alternate 
with the sepals; that is to say, the 
centre of each petal is immediately over 
or within the interval between the 
sei.ials. Petalodeus — W heie a double 
flower is foii;jt 5 d l.»y tho tran-sformation 
of any (d the parts about tho corolla 
into pctal-like expansions. Petaloid 
— R esembling petals. 
PETAf.OM.v'NiA — Petal madness. A inon- 
.sti’oiis developnnnit of parts in the 
fluwor, not belonging t‘> tlm ctjrolhi, 
into pctal-like expansions. 
PetToek, PETi’oi.fs— The stalk or su]ipurfc 
by which the blude or limb of a leaf 
is attaehi’d to tho stem. I^etiola'ted — 
Furnished with a petiole or leafstalk. 
The sejiarate stalk of each leaflet in a 
compound leaf is termed a potiolule. 
