lxii 
INTRODUCTION 
Panicle. — A genera .name for loosely 
branched inflorescences, such as that 
of .the Horse Chestnut and many 
Grasses, as Panicum plicatum, p. 583. 
More strictly, a panicle is a compound 
inflorescence, which may be spicate, 
racemose, corymbose or cymose in 
composition. 
Papilionaceous. — Shaped like a butter- 
fly. Applied more especially to the 
flowers of the Pea farqily. In such 
flowers the upper petal is the standard , 
the lateral petals the wings, and the 
lower petals combined the keel. 
Pappus. — The calyx-limb of the 
Compositse, usually composed of 
hairs or bristles, less frequently of 
scales. See Aster, p. 250, Serratula, 
p. 275, Ainslicea, p. 277. 
Parasite. — A plant that grows upon and 
roots into the tissues of another from 
which it obtains its nourishment, as 
Cuscuta, p. 340, and Viscum, p. 440. 
Pedicel. — A flower-stalk ; properly the 
ultimate branchlets of a compound 
inflorescence, each bearing one 
flower ; but often employed instead of 
peduncle. 
Peduncle. — When flowers are solitary, 
as in the axils of the leaves, the stalk 
is termed a peduncle. It is also 
employed to designate the stalk of a 
cluster or head of flowers, as in the 
Composite. 
Peltatus. — Produced from within the 
margin, as the leaf -stalks of Cissam- 
pelos, p. 19. 
Perennial. — Flowering more than once 
from the' same root or root-stock, 
more especially applied to herbs that 
die down annually. 
Perianth. — The floral envelopes collec- 
tively ; but employed more especially 
where there is only one series or 
where there is no distinct differentia- 
tion into calyx and corolla. 
Pericarp. — The shell of a fruit or seed- 
vessel. It consists of distinct parts 
in some fruits ; thus in the Peach 
there is the skin or epicarp, the flesh 
or mesocarp, and the stone or endo- 
carp. 
Perigynous. — Growing on the tube or 
throat of the calyx, as the petals and 
stamens in most of the Rosacese. 
Persistent. — Of more than ordinary 
duration, as the calyx of the Straw- | 
berry, the style in many Cruciferse, 
and the leaves of evergreens. 
Petals. — The separate or united parts of 
the floral envelope. See Corolla. 
Petaloid. — Resembling petals in colour 
and texture, commonly applied to the 
perianth of the Lilies and other 
monocotyledonous orders. 
Petiolate. — Having a stalk. 
Petiole. — A leaf -stalk. 
Petiolule. — The stalk of a leaflet. 
Phcenogamous or Phanerogamous . — 
Having manifest flowers in contra- 
distinction to ferns, which are 
designated Cryptogamous.. 
Pinnate. — A compound leaf divided into 
leaflets. There are simply pinnate 
leaves, Cedrela, p. 82, Indigofera, p. 
122, and bipinnate leaves, Albizzia, 
p. 154, and others of greater degrees 
of division. There are no buds in 
the axils of a leaflet. 
Pinnatifid. — As applied to leaves and 
other organs, signifies that they are 
lobed or divided, but not quite to the 
midrib. 
Pinnule. — Pinnules are the primary 
divisions of a bipinnate leaf ; leaflets 
are the primary divisions of a pinnate 
leaf and the secondary divisions of a 
bipinnate leaf. 
Pistil. — The female organs of a flower 
collectively. It consists of one car- 
pel, as in Leguminosse ; of several 
free carpels, as in the Buttercup ; or 
of several combined carpels, as in 
Flax. The simplest form of pistil 
consists’ of an ovary and stigma, but 
the latter usually has a stalk or style. 
Some authors call the carpels of a 
fruit pistils when they are free, as in 
the Buttercup. 
Placenta. — The process or body which 
bears the ovules in the ovary. 
Plumose. — Feathery, as the pappus of 
Ainslicea, p. 277, and the ripe achenes 
of Clematis, p. 3. 
Plumule. — The primary bud of an 
embryo. 
Pollen . — The powdery substance formed 
in the anthers. It consists of minute, 
unicellular bodies whose function 
is to fertilise the ovules, and it is 
thus regarded as the male element in 
sexual reproduction. 
Polygamous . — When male, female and 
hermaphrodite flowers are intermixed 
on the same individual plant. 
Polypetalous. — Petals free, as in the 
Buttercup. 
Prcecox. — Flowering early. 
Pratensis. — Growing in meadows. 
Procumbent. — Applied to stems that lie 
on the ground but do not form roots 
at the joints. 
Pubescent. — Clothed with short, soft 
hairs. 
Putamen. — The stone of a fruit such as 
the Peach. 
Raceme . — A kind of inflorescence in 
which the flowers are nearly equally 
stalked and arranged singly on a 
common axis or peduncle, as in Astra- 
galus chlorostachys, p. 126. 
Rachis, Rachilla . — See Rhachis. 
Radical . — Proceeding from the crown 
of the root or root-stock, as the 
