4,295 articles
Pea
Pea (Pisum sativum), a founder-crop legume domesticated about 10,000 years ago in the Near East with a second Ethiopian domestication (P. abyssinicum); grown as English shelling, snow, and sugar snap peas, a cool-season crop harvested in about 60 days.
Pea shoots
Pea shoots are the young, tender vine tips of garden peas (Pisum sativum), a Hmong-introduced specialty green eaten raw, steamed, or stir-fried; rich in vitamins C, E, A, and potassium, grown in cool 55–65°F weather, and used within one to two days of harvest.
Peach (桃)
Peach (桃; Prunus persica), a Rosaceae stone fruit domesticated in China's lower Yangzi valley from at least 8000 BP, spread via the Silk Road through Persia; China grows about 70 percent of world production.
Peach gum
Peach gum (桃胶), the injury-induced exudate of Prunus persica, yields type II arabinogalactan polysaccharides with arabinose and galactose as main sugars; extracted fractions emulsify better than gum arabic.
Peanut
Peanut (Arachis hypogaea), groundnut: a Fabaceae legume whose flowers pollinate above ground while pods ripen underground (geocarpy). Fourth-ranked global oilseed; ~50 Mt/year led by China, India, Nigeria; key allergen and aflatoxin risks.
Pear
Pear, Pyrus communis and Asian Pyrus species, a temperate pome fruit from the rose family; world production about 26 million tons, propagated by grafting, self-unfruitful, and menaced chiefly by fire blight (Erwinia amylovora).
Pearl millet (बाजरा)
Pearl millet (बाजरा, bajra; Pennisetum glaucum, Cenchrus americanus), the most widely grown millet, domesticated in the western African Sahel, spread to India by 4000–3500 years ago; drought-hardy staple of Sahel and India.
Peat
Peat: partially decomposed plant matter formed in waterlogged bogs and fens, accumulating 0.5–1 mm yearly. Covers ~3% of land but stores a third of Earth's carbon; extracted for fuel and horticulture, driving major emissions when drained.
Pecan
Pecan (Carya illinoinensis), also called sweet pecan or Illinois nut, a North American hickory tree grown for its edible nut; US produces ~80% of world crop, 284 million lb in 2025, with LDL-lowering trial evidence.
Pecluma
Pecluma M.G.Price is a Neotropical fern genus in Polypodiaceae, Polypodioideae, segregated from Polypodium in 1983; about 40-52 species from Florida to northern Argentina, with several Polypodium species nested within it and Miocene Dominican amber fossils.
Pecopteris
Pecopteris, a Brongniart 1822 form genus of late Paleozoic fern foliage, chiefly marattialean tree ferns like Psaronius; common Carboniferous-Permian fossil with whole-base pinnules, stretched 350% in a Rhode Island specimen.
Pedaliaceae
Pedaliaceae R.Br., the sesame family, is a Lamiales family of mucilage-gland-covered herbs and shrubs from warm regions, with about 11 accepted genera including Sesamum (sesame), Harpagophytum (devil's claw), and the Malagasy Uncarina.
Pedicularis
Pedicularis (louseworts), largest genus of Orobanchaceae with about 600-681 hemiparasitic herb species, North Temperate mountains, center of diversity in the Himalaya-Hengduan Mountains; noted for floral diversity, homoplasy, and traditional medicinal use.
Peganum
Peganum (Nitrariaceae, formerly Zygophyllaceae) is a genus of perennial herbs native from the Mediterranean to India and Texas to NE Mexico; P. harmala yields harmine and harmaline alkaloids used in traditional medicine.
Peganum harmala
Peganum harmala (Syrian rue, harmal) is a perennial Nitrariaceae herb native from the Mediterranean to Mongolia and India, whose seeds' β-carboline alkaloids harmine and harmaline act as reversible MAO-A inhibitors, giving folk-medicinal, psychoactive, and toxic properties.
Pelargonium
Pelargonium (geraniums, stork's-bill genus), a Geraniaceae genus of ca. 280 species mostly from southern Africa, with zygomorphic nectar-spurred flowers, four subgenera, and horticulturally important scented species like P. graveolens.
Pelargonium graveolens
Pelargonium graveolens (rose geranium, rose-scented pelargonium) is a strongly aromatic southern African subshrub, Geraniaceae, source of rose geranium essential oil rich in citronellol and geraniol, used in perfumery, food, and traditional medicine.
Pellia
Pellia (Raddi 1818) is a genus of simple thalloid liverworts in Pelliaceae, Pelliales, Jungermanniopsida, with five species in Pellia and three in Apopellia, basal among simple thalloids, Northern Hemisphere temperate.
Pellia epiphylla
Pellia epiphylla (common or overleaf pellia), a common thalloid liverwort (Pelliaceae) of streams and wet acidic soils in Europe and North America; monoicous, with cryptic N and S lineages parent to allopolyploid P. borealis.
Peltophorum
Peltophorum (Vogel) Benth., yellow-flowered trees of Fabaceae subfamily Caesalpinioideae, also called Baryxylum; seven accepted species, pantropical, sister to Bussea, used as ornamentals, timber, fodder, and medicine.
Penstemon
Penstemon (beardtongues), genus Penstemon Schmidel of Plantaginaceae, is the largest flowering-plant genus endemic to North America, with roughly 250–280 mostly western species, bee- and hummingbird-pollinated syndromes, and many rare edaphic endemics.
Pentadesma butyracea
Pentadesma butyracea (butter tree, tallow tree) is a West and Central African Clusiaceae tree up to 35 m whose seeds yield an edible butter rich in oleic and stearic acids, used in food, cosmetics, and traditional medicine.
Pentagramma triangularis
Pentagramma triangularis, the gold-back fern (gold fern, goldenback fern), a perennial Pteridaceae fern native from Vancouver Island to Baja California, with white or yellow farina on frond undersides, rock-crevice habitat, and a 1990 taxonomic revision splitting it from Pityrogramma.
Peony
Peony (Paeonia L.), sole genus of Paeoniaceae in Saxifragales, about 33-37 species of herbaceous and tree peonies native from Europe and temperate Asia to western North America; grown for ornament, traditional medicine (paeoniflorin, paeonol), and oil.
Peperomia
Peperomia (radiator plant) is a genus of over 1,300 species of often succulent Piperaceae herbs, native to tropics and subtropics, mostly tropical America, spanning C3 to CAM photosynthesis and popular as foliage houseplants.
Peperoncino
Peperoncino, the Italian name for hot chili peppers (Capsicum, especially C. annuum), brought from the Americas by Columbus in 1493; central to Calabrian cooking and registered as Peperoncino di Calabria PGI in 2026.
Peppermint
Peppermint (Mentha × piperita) is a sterile hybrid mint, a cross between water mint and spearmint, grown for menthol-rich oil used in flavoring and medicine.
Perennial
Perennial: a plant living multiple years, regrowing from crown, rhizomes, or roots, unlike annuals. Covers herbaceous vs woody perennials, winter dormancy, garden care, and perennial grain crops such as Kernza.
Perennials
Perennials (stauder) are herbaceous plants that die down yearly and regrow from underground parts. The Copenhagen Botanical Garden's perennial quarter holds over 1,000 species, alphabetically ordered, showing wild ancestors of garden plants.
Pericopsis elata
Pericopsis elata (afrormosia, African teak, kokrodua) is an endangered Fabaceae timber tree of West and Central African semi-deciduous forest, CITES Appendix II since 1992, traded as logs, sawn wood, and veneer.