3,306 articles
Pinus roxburghii
Pinus roxburghii, chir pine or long-leaved Indian pine (चीड), a Himalayan pine from Pakistan to NW India at 450–2300 m; dominant resin and timber tree, IUCN Least Concern, needles in threes, fire-resistant.
Pinus sibirica
Pinus sibirica (Siberian pine, Siberian stone pine, 西伯利亚五针松) is a five-needled taiga pine of NE Europe to N China, grown for edible cedar nuts, oil, and timber; closely related to Pinus cembra.
Pinus strobus
Pinus strobus, eastern white pine (northern white pine, Weymouth pine), a large five-needled North American conifer up to 150 ft tall, valued timber species threatened by white pine blister rust and white pine weevil.
Pinus subg. Strobus
Pinus subg. Strobus, the white or soft pines, is one of the two subgenera of the genus Pinus, holding about 48 species including white pines, stone pines, and pinyons.
Pinus sylvestris
Pinus sylvestris, Scots pine, is the most widely distributed pine in the world, native from Scotland to Siberia. A 15–30 m two-needle pine, fire-adapted, shade-intolerant, and the tree of Scotland's Caledonian pinewoods.
Pinus tabuliformis
Pinus tabuliformis, known as Chinese pine and Chinese red pine, is a coniferous tree native to China and Korea, and is the principal afforestation species of northern China.
Pinus taeda
Pinus taeda, the loblolly pine, is a needled evergreen pine native to the central and southeastern United States, the South's most important timber species on roughly 29 million acres.
Pinus thunbergii
Pinus thunbergii, Japanese black pine (kuromatsu, haesong), a coastal conifer native to Korea and central/southern Japan, used for erosion control and bonsai, threatened by pine wilt disease, Least Concern, invasive in parts of eastern North America and New Zealand.
Pinus virginiana
Pinus virginiana, Virginia pine (scrub pine, Jersey pine), a small two-needle pine of the eastern United States, a shade-intolerant pioneer on dry uplands, grown for pulpwood, Christmas trees, and mine-spoil reclamation.
Pinus yunnanensis
Pinus yunnanensis, the Yunnan pine, is a pine native to south-central China and northern Myanmar, named in 1899. It dominates Yunnan-Guizhou Plateau forests at 700 to 3000 m.
Pinyon–juniper woodland
Pinyon–juniper woodland (PJ woodland), semiarid North American vegetation of pinyon pines and junipers covering over 190,000 km² of the western US; three types (persistent woodlands, savannas, wooded shrublands), centennial fire cycles, post-settlement expansion, and pinyon jay decline.
Piper (plant)
Piper, also known as the Piper genus, is a genus of flowering plants in the pepper family, comprising roughly 2,400 to 2,600 tropical species including black pepper and betel.
Piper aduncum
Piper aduncum (spiked pepper, matico) is a 2–7 m Piperaceae shrub native from Mexico to tropical South America, invasive in the Pacific and Southeast Asia, used in traditional medicine and as a dillapiol-rich essential oil source.
Piperaceae
Piperaceae, the pepper family, is a pantropical Piperales family of five genera and 3,000–3,600 species, dominated by Piper (black pepper, betel, kava) and Peperomia, with three subfamilies and a Late Cretaceous fossil record.
Piperales
Piperales, a magnoliid order of flowering plants (pepper family, Piperaceae; birthwort family, Aristolochiaceae), about 4,200 species in 16 genera, largest angiosperm order outside eudicots and monocots, includes black pepper Piper nigrum.
Pistachio
Pistachio, the nut of Pistacia vera, a dioecious wind-pollinated Anacardiaceae tree native to Central Asia and northeast Iran; alternate-bearing crop led by the United States, with mandatory aflatoxin testing and about 3 acre-feet water per acre in California.
Pistacia atlantica
Pistacia atlantica (Atlas pistachio, Mt. Atlas mastic tree, Bétoum) is an Anacardiaceae tree native from the Canary Islands and Mediterranean to the W. Himalaya, drought-tolerant, resin- and gall-producing, IUCN near threatened.
Pistacia lentiscus
Pistacia lentiscus, the mastic tree or lentisk, a Mediterranean Anacardiaceae shrub; source of mastic resin, Chios mastic gum (var. chia), EMA traditional herbal medicine for dyspepsia and minor wounds.
Pistacia terebinthus
Pistacia terebinthus, the terebinth or turpentine tree, is a Mediterranean Anacardiaceae shrub or tree; fruit eaten as snack or coffee-like drink, resin used medicinally, IUCN Least Concern.
Pistia
Pistia stratiotes (water lettuce, jalkumbhi), sole species of genus Pistia in Araceae, is a free-floating pantropical aquatic herb that forms dense invasive mats and is widely used in wastewater phytoremediation.
Pitcairnioideae
Pitcairnioideae, a subfamily of Bromeliaceae (bromeliads), traditionally the terrestrial, spiny-leaved group with dry capsules and winged seeds; molecular work split it, leaving five genera including Pitcairnia, Dyckia, and Deuterocohnia.
Pitcher plant
Pitcher plants are carnivorous plants with pitfall-trap leaves that digest prey in fluid; unrelated lineages Nepenthes, Sarracenia, Darlingtonia, Heliamphora, and Cephalotus evolved them independently in nutrient-poor wetlands.
Pith
Pith is the central ground tissue, usually parenchyma, inside the vascular cylinder of stems and roots; it can form aerenchymatous cavities, responds to shade and submergence, and was named by Theophrastus.
Pithecellobium
Pithecellobium (blackbead) is a genus of spiny mimosoid legume trees and shrubs in Fabaceae, tribe Ingeae, native from Mexico to Brazil and Florida to the Caribbean, with about 21 accepted species including the Madras thorn, Pithecellobium dulce.
Pithecellobium dulce
Pithecellobium dulce, Manila tamarind, Madras thorn, guamúchil, kamachile: a spiny Fabaceae tree native from Mexico to Peru, grown for its sweet edible seed aril, fodder, and timber, and invasive in Hawaii, Florida, and India.
Pittosporum
Pittosporum (Banks ex Gaertn.) is the largest genus of Pittosporaceae (Apiales), about 150-200 species of trees and shrubs with sticky-resin-coated seeds, native from Africa and Asia to Australia and the Pacific, absent from the Americas; includes ornamentals and the invasive P. undulatum.
Plant physiology
Plant physiology: the study of how plants function, covering photosynthesis, respiration, transpiration, xylem water transport, mineral nutrition, and stress responses; founded experimentally by Stephen Hales in 1727.
Plantaginaceae
Plantaginaceae, the plantain family (Lamiales), about 2,100 species in ~106 genera worldwide; expanded from polyphyletic Scrophulariaceae, 12 tribes, includes Plantago, Antirrhinum, Digitalis, Penstemon, Veronica.
Plantago
Plantago (plantains) is a cosmopolitan genus of about 246 accepted herb species in Plantaginaceae, with rosette leaves, spike inflorescences, and mucilaginous seeds; P. ovata yields psyllium husk, and P. lanceolata and P. major are global weeds and ecological models.
Plantago coronopus
Plantago coronopus, buck's-horn plantain, is a salt-tolerant Plantaginaceae herb native from Europe to Central Asia, with lobed rosette leaves eaten in salads, four subspecies, and introduced invasive populations in Korea, Australia, and the Americas.