pennywort
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.
Any of several not closely related plants around the world, generally with round leaves of about the shape and size of a penny.

pennyworts
plural of pennywort

peonies
plural of peony

peony
A flowering plant of the genus Paeonia with large fragrant flowers.
A dark red colour.

pepper tree
New Zealand native shrubs Pseudowintera axillaris and Pseudowintera colorata with leaves often having large red blotches and are used for traditional medicines, and whose flowers are greenish yellow and its fruit is orange-red or black.
Any of the South American trees in the genus Schinus, which have small fruits that have been used as a substitute for black pepper.

pepperbushes
plural of pepperbush

pepperidge
Nyssa sylvatica, a medium-sized deciduous tree of North America.

pepperidges
plural of pepperidge

peppertree
Alternative form of pepper tree.

peppertrees
plural of peppertree

peridium
The outer layer that covers the spore-bearing organ in many fungi.

peridiums
plural of peridium

persimmon
The orange fruit of any of various species of trees in the genus Diospyros, especially Diospyros kaki (the kaki or Japanese persimmon) or Diospyros virginiana (the wild American persimmon), which is sweet when ripe and astringent when immature.
The tree this fruit grows on, generally one of two species of ebony: Diospyros kaki (Asian) or Diospyros virginiana (North American).

persimmons
plural of persimmon

persimon
Dated form of persimmon.

persimons
plural of persimon

phacelia
Any of many annual or perennial herbaceous plants, of the genus Phacelia, native to the Americas.

phacelias
plural of phacelia

phyllites
plural of phyllite

phytolacca
Any of the genus Phytolacca of herbaceous plants; the poke or pokeweed.

phytolaccas
plural of phytolacca

pickleweeds
plural of pickleweed

pigeonberries
plural of pigeonberry

pigeonberry
The red berry of Rivina humilis, a flowering plant in the pigeonberry family Petiveriaceae.

pigeonwood
Oriental trema, an evergreen tree of species Trema orientalis, widely distributed throughout much of the tropics.
A tree of species Hedycarya arborea, endemic to New Zealand.
Sea grape (Coccoloba uvifera).

pigeonwoods
plural of pigeonwood

pigweed
Any of various weedy plants sometimes used as pig fodder
Any of various weedy plants sometimes used as pig fodder:
Any of various weedy plants sometimes used as pig fodder:
Any of various weedy plants sometimes used as pig fodder:
Any of various weedy plants sometimes used as pig fodder:
Any of various weedy plants sometimes used as pig fodder:

pigweeds
plural of pigweed

pilei
plural of pileus

pileus
The cap of a mushroom.
The bell of a jellyfish.
A small thin cloud attached to a cumulus cloud.
A conical felt hat worn in Ancient Rome and Greece.
The top of the head of a bird, from the bill to the nape.

pilinuts
plural of pilinut

piloi
plural of pilos.

pilos
Alternative form of pileus (“ancient hat”).

pilpil
Boquila trifoliolata.

piney
Alternative spelling of piny.

pinkroot
A perennial North American herb (Spigelia marilandica), sometimes cultivated for its showy red blossoms.
An annual South American and West Indian plant (Spigelia anthelmia).
The root of Spigelia marilandica or Spigelia anthelmia, used as a powerful vermifuge.

pinkroots
plural of pinkroot

pinweed
Any of the genus Lechea of low North American herbs with branching stems, and very small and abundant leaves and flowers.

pinweeds
plural of pinweed

pioney
Obsolete spelling of peony.

pioneys
plural of pioney

pionies
plural of piony

piony
Obsolete form of peony.

piperidge
Alternative form of pepperidge.

piperidges
plural of piperidge

pipevine
A vine of genus Aristolochia.

pipevines
plural of pipevine

pipewort
Any of several aquatic plants of the genus Eriocaulon.

pipeworts
plural of pipewort

pipperidge
Alternative form of pepperidge.

pipperidges
plural of pipperidge

pishamin
Obsolete form of persimmon.

pisonia
Any of the genus Pisonia of nyctaginaceous flowering plants.

pisonias
plural of pisonia

pitseed goosefoot
Chenopodium berlandieri, a North American herb, sometimes cultivated.

pokeberries
plural of pokeberry

pokeberry
Synonym of pokeweed (the plant Phytolacca americana or its dark red or purple fruit).

pokeroot
Synonym of pokeweed.

pokeroots
plural of pokeroot

pokeweed
A poisonous North American plant, Phytolacca americana, with reddish stems, broad leaves, clusters of white flowers, and dark purple berries.

pokeweeds
plural of pokeweed

policeman's helmet
The invasive plant Impatiens glandulifera, native to the Himalayas.
Used other than figuratively or idiomatically: see policeman, helmet.

polygala
Any milkwort of the genus Polygala

polygalas
plural of polygala

pondweed
Any of several plants that grow in ponds or similar aquatic conditions:
Any of several plants that grow in ponds or similar aquatic conditions:
Any of several plants that grow in ponds or similar aquatic conditions:
Any of several plants that grow in ponds or similar aquatic conditions:
Any of several plants that grow in ponds or similar aquatic conditions:
Charales, an order of green algae

pondweeds
plural of pondweed

popweed
bladderpod

porkwood
The wood of the spekboom tree (Portulacaria afra).

possumhaw
deciduous holly, Ilex decidua.
Viburnum nudum

potamogeton
Any of the plants of the genus Potamogeton.

potamogetons
plural of potamogeton

potato bush
An Australian shrub, Solanum ellipticum

prickly hornwort
Ceratophyllum muricatum, a freshwater plant, of cosmopolitan distribution.

prickly saltwort
Salsola kali (syn. Kali turgidum), a coastal, halophilic, annual plant, with succulent, spiny leaves.

princess tree
An Asian deciduous hardwood tree of the species Paulownia tomentosa, which also thrives invasively in North America and Europe.

princewood
The wood of various rubiaceous trees, including those of species Hamelia ventricosa, Cordia gerascanthus, and Exostema caribaeum.

procumbent pigweed
Synonym of mat amaranth.

prostrate amaranth
Synonym of mat amaranth.

prostrate pigweed
Synonym of mat amaranth.

protium
The lightest and most common isotope of hydrogen, having a single proton and no neutrons: 11H. It is the only stable nuclide with no neutrons.
An atom of this isotope.

protiums
plural of protium

puncture vine
A creeping weed with strong thorns on its fruits capable of puncturing bicycle tires, Tribulus terrestris.

puncturevine
Alternative form of puncture vine.

puncturevines
plural of puncturevine

purple plague
The brittle, bright-purple intermetallic compound AuAl₂, formed when gold and aluminium are heated while in direct contact (for instance, if a gold wire is bonded to an aluminium contact pad and experiences heating due to electrical resistance).
The problems caused by the formation of this compound, including the formation of voids in the contact area and the potential for fracture of the gold-aluminium junction.

purpletop vervain
A purple flowering verbena (Verbena bonariensis, family Verbenaceae) native to South America and widely cultivated as a flowering annual or herbaceous perennial.