North American Orchid Conservation Center

Glossary: P

palate palate
A raised area on a lower lip of a two-lipped corolla that obscures or blocks the mouth.
palea palea
In grasses (Poaceae), the inner of the two bracts enclosing the floret; in composites (Asteraceae), the chaff (bracts) of the disk florets of the receptacle.
palmate palmate
With parts radiating from a common point, like fingers of a hand.
palmately compound palmately compound
A leaf comprised of separate leaflets that radiate from a common point, like parts of a fan.
palmately lobed palmately lobed
With projections that radiate from a common point, as fingers in a hand.
pandurate pandurate
Fiddle-shaped (constricted in the middle).
panicle panicle
A branched, indeterminate flower cluster (inflorescence) with individual flowers on stalks (pedicels).
Papilio glaucus Papilio glaucus
Eastern Tiger Swallowtail, photo ©Herman Giethoorn .
papilionaceous papilionaceous
Shaped like a pea-flower, with an upright banner petal, two lateral wing petals, and two lower petals fused into a keel.
Papilio palamedes Papilio palamedes
Palmedes Swallowtail, photo ©Sturgis McKeever, Georgia Southern University, Bugwood.org.
Papilio polyxenes Papilio polyxenes
Black Swallowtail, photo ©Herman Giethoorn .
Papilio troilus Papilio troilus
Spicebush Swallowtail, photo ©Jim Fowler .
papilla papilla
A short, rounded, blunt projection.
papillate papillate
Covered with small, soft projections.
pappus pappus
A series of scales, hairs or bristles surrounding the tip of the achene in Asteraceae.
parallel veins parallel veins
With veins that run side-by-side at the same angle and do not converge, often arranged parallel to the midvein of the leaf blade.
parapinnate parapinnate
A compound leaf in which all the leaflets are paired, with no terminal leaflet (compare with imparapinnate).
parasitic parasitic
Living on, and deriving nutrients from, another organism (usually to the disadvantage of the host).
Paratrea plebeja Paratrea plebeja
Plebian Sphinx Moth, photo ©Mark J. Dreiling, North American Moth Photographers Group.
pectinate pectinate
Comb-like.
pedicel pedicel
The stalk of a single flower in an inflorescence.
pedicellate pedicellate
Borne on a pedicel.
peduncle peduncle
A stalk that supports an inflorescence composed of 1 or more flowers.
pedunculate pedunculate
Borne on a peduncle.
pellucid
Transparent or translucent.
pelotons pelotons
Coils of fungal hyphae.
peltate peltate
Round and attached at the middle, like a mushroom to its stalk.
pendulous pendulous
Hanging down.
penicillate penicillate
With a tuft of hairs at the top.
penultimate
Next-to-last.
pepo pepo
A large, thick-walled leathery berry as in a pumpkin, derived from an inferior ovary.
perennating
Surviving the winter or dormant season.
perennial
A plant that lives more than two years.
perfect perfect
With both male and female organs on the same flower.
perfoliate perfoliate
The bases of a leaf or two opposite leaves join around a stem so that the stem appears to pass through the leaf or leaf pair.
perianth perianth
The whorls of sepals (calyx) and/or petals (corolla) that enclose the reproductive parts of an angiosperm flower.
pericarp pericarp
The mature ovary wall of a fruit.
perigynium perigynium
A membrane sac enclosing the flower and later, the fruit (achene) of Carex species.
perigynous perigynous
With a superior ovary that has a hypanthium.
persistent
A leaf or organ that remains attached to the plant throughout the year or after performing its normal function; evergreen.
perulate perulate
Covered with 1 or more scales, as in the winter buds of woody plants.
petal petal
One of the hightly modified leaves of a flower, usually pigmented and attracting pollinators.
petaloid petaloid
An organ such as a sepal that resembles a typical flower petal in color and shape.
petiolate petiolate
With a petiole (leaf stalk).
petiole petiole
Stalk of a leaf that bears the blade.
petiolule petiolule
Stalk of a leaflet in a compound leaf.
Phoebis sennae Phoebis sennae
Cloudless Sulphur Butterfly, photo ©Jim Fowler .
photosynthesis
A series of chemical reactions by which plants use light energy to convert carbon dioxide into carbohydrates.
phyllary phyllary
One of the many leaf-like bracts that surround the base of the capitulum in Asteraceae; synonym "involucral bract".
phyllopodic phyllopodic
With blade-bearing leaves arising only from the base of the plant (center of parent shoot).
Phyprosopus callitrichoides Phyprosopus callitrichoides
Curve-lined Owlet Moth, photo ©Mike Boone, North American Moth Photographers Group.
Pieris rapae Pieris rapae
Cabbage White Butterfly, photo ©Alan Cressler.
pilose pilose
With sparse, thin, spreading hairs.
pinna pinna
Leaflet of a fern frond.
pinnate pinnate
Once-divided, as with ferns with fronds divided into pinnae.
pinnately compound pinnately compound
A leaf comprised of leaflets that are arranged along both sides of an elongate axis, as in a feather.
pinnately lobed pinnately lobed
With projections on each side of an axis, as in a leaf with lobed margins on both sides of the midvein.
pinnatifid pinnatifid
Not quite divided all the way to a midrib of a leaf, i.e. without separate leaflets.
pistil pistil
The ovule-bearing parts of a single flower, composed of one or more carpels that are usually differentiated into an ovary, style, and stigma.
pith pith
Internal tissue of a stem or root.
placenta placenta
The part of the ovary to which the ovules or seeds are attached; placentation describes the arrangement of the placenta in the ovary.
placentation placentation
How the ovules in an ovary are attached to it.
plane plane
Flat; the orientation of a flat surface.
planoconvex planoconvex
In cross-section, with one flat surface and one convex surface.
plantlet plantlet
A tiny plant that is produced vegetatively and is identical to the parent plant.
pleated
Indented in a long line; usually describing a leaf.
plumose plumose
Feathery.
Plusia nichollae Plusia nichollae
Looper Moth, photo ©John Davis, North American Moth Photographers Group.
pod pod
A dry, dehiscent fruit enclosing a hollow space with one or more seeds; a legume is a type of pod.
Poecilognathus punctipennis Poecilognathus punctipennis
Bee Fly, photo ©Mary Keim.
Polites mystic Polites mystic
Long Dash Skipper, photo ©David Cappaert, Michigan State University, Bugwood.org.
Polites peckius Polites peckius
Peck's Skipper, photo ©David Cappaert, Bugwood.org.
pollen pollen
The sperm-bearing microgametophyte of seed plants.
pollinarium pollinarium
A pair of pollinia plus the structures holding them together (in orchids and some other plants).
pollination
The process by which pollen is transferred to a receptive stigma.
pollinator
An agent such as an insect or animal that transfers pollen between plants.
pollinium pollinium
An aggregation of pollen grains in orchids and some other plants (plural: pollinia).
Polychrysia morigera Polychrysia morigera
Disjunct Looper Moth, photo ©Jim Vargo, North American Moth Photographers Group.
polygamous polygamous
With both unisexual and bisexual flowers on the same plant.
pome pome
A fleshy fruit derived from a compound, inferior ovary, with a papery or bony inner ovary wall (endocarp) that usually encloses several seeds, as in an apple.
pore pore
Small hole.
posterior posterior
Positioned in back of.
prairie
Habitat dominated by warm-season, perennial grasses.
precocious
When flowers expand before the leaves.
prickle prickle
Small, more or less sharp outgrowth of the epidermis, which does not contain a vascular bundle.
primocane primocane
The first-year, non-reproductive stem produced by raspberries and blackberries (Rubus species).
procumbent procumbent
Trailing or prostrate.
prohibited
A species banned for sale or distribution due to invasiveness.
propagule
A reproductive body such as a seed, bulb, or turion.
prophyll prophyll
A bract subtending a branching inflorescence (or a perianth in Juncus).
prostrate prostrate
Lying flat along the ground.
Protambulyx shigilis Protambulyx shigilis
Streaked Sphinx Moth ©Jim Vargo.
Protoboarmia porcelaria Protoboarmia porcelaria
Porcelain Gray, photo ©David Stephens, Bugwood.org.
protocorm protocorm
First stage of growth after an orchid seed germinates.
proximal proximal
Produced near the base of a structure (compare with distal).
Pseudaletia unipuncta Pseudaletia unipuncta
True Armyworm, photo ©John Capinera, University of Florida, Bugwood.org.
pseudanthium
A cluster of small flowers that appear to be a single flower, as in species of Benthamidia (big-bracted dogwoods) or any number of members of the Asteraceae (aster family).
pseudobulb
A thickened or bulb-like stem that functions as a storage organ.
pseudoterminal bud pseudoterminal bud
A bud at the tip of a branch that resembles a terminal bud but shows both a leaf bundle scar and a twig bundle scar near its base.
pseudowhorl pseudowhorl
Actually alternate but with nodes so crowded that the organs appear whorled.
puberulent puberulent
With tiny hairs barely visible to the naked eye.
pubescence pubescence
Hairs.
pubescent pubescent
Bearing hairs.
punctate punctate
Marked with dots or translucent glands.
pustule pustule
Blister.
pyramidal pyramidal
Shaped like a pyramid (three-dimensional triangle).
Pyrausta perrubralis Pyrausta perrubralis
Shasta Pyrausta Moth, photo ©John Davis, North American Moth Photographers Group.
pyrene pyrene
Stone: the seed plus a hard layer of endocarp surrounding it.
pyxis pyxis
A dehiscent fruit that splits open around the middle like a box, with the top falling off and exposing the seed(s).