4,295 articles
Prunus spinosa
Prunus spinosa, blackthorn or sloe, a spiny Rosaceae shrub native from Europe to Central Asia, Iran and NW Africa. White flowers before leaves, astringent sloe fruits used for sloe gin and pacharán; IUCN least concern.
Prunus subg. Cerasus
Prunus subg. Cerasus, the true cherries, is a subgenus of Prunus (Rosaceae) with about 50 Northern Hemisphere species including sweet cherry, sour cherry, and ornamental sakura; it originated in the Eastern Mediterranean–Central Asia before 11.57 Mya.
Prunus virginiana
Prunus virginiana (chokecherry), Rosaceae, a thicket-forming North American shrub or small tree with three varieties (virginiana, melanocarpa, demissa), astringent dark drupes, rhizomatous spread, strong fire resprouting, and hydrocyanic-acid pits.
Pseudobulb
Pseudobulb: a thickened, bulblike modified stem above ground in many orchids (Cattleya, Dendrobium, Bulbophyllum), storing water, food, and CO2 in aerenchyma for CAM photosynthesis; old leafless ones are backbulbs used for propagation.
Pseudolarix (金钱松属)
Pseudolarix (金钱松属), golden larch, is a monotypic Pinaceae genus whose sole species Pseudolarix amabilis is a Vulnerable deciduous conifer from eastern China, unrelated to true larches, with gold autumn foliage and shattering cones.
Pseudolarix wehrii
Pseudolarix wehrii (Gooch, 1992) is an extinct Eocene golden larch (Pinaceae) from Washington and Arctic Canada, a long-bracted fossil species distinguished from living Pseudolarix amabilis by bracts over half the cone-scale length.
Pseudoroegneria spicata
Pseudoroegneria spicata, bluebunch wheatgrass (beardless wheatgrass in subsp. inerme), is a native cool-season perennial bunchgrass of western North American sagebrush steppe, a leading rangeland restoration grass with cultivars Whitmar, Goldar, P-7, and Anatone.
Pseudotsuga
Pseudotsuga (douglas-firs), Pinaceae conifer genus, 1867 Carrière; four species, P. menziesii (Douglas-fir), macrocarpa, sinensis, japonica; native western North America and East Asia; distinctive protruding cone bracts.
Psidium
Psidium (guava genus), Myrtaceae, native Mexico to tropical America, 71-92 species including cultivated Psidium guajava and invasive strawberry guava Psidium cattleyanum, one of the world's 100 worst invasive organisms.
Psidium guajava
Psidium guajava, the common guava, is a Neotropical Myrtaceae fruit tree grown across the tropics; Brazilian Amazonia is its probable domestication origin, and its fruit is exceptionally rich in vitamin C (230–1,426 mg/100 g).
Psilotum
Psilotum, the whisk ferns, a genus of two rootless, leafless vascular plants (P. nudum, P. complanatum) in Psilotaceae, native to tropics and subtropics, now placed within the ferns near Ophioglossaceae.
Psilotum complanatum
Psilotum complanatum (flatfork fern, moa nahele), a flattened-stemmed whisk fern of Psilotaceae from tropical America, Asia, and the Pacific; now treated as the hybrid Psilotum x complanatum between P. nudum and P. flaccidum.
Psilotum nudum
Psilotum nudum (whisk fern, moa in Hawaii) is a rootless, leafless eusporangiate fern of Psilotaceae with forked aerial shoots and three-fused sporangia (synangia), pantropical in distribution, once called a living fossil but now placed near Ophioglossaceae within true ferns.
Psophocarpus
Psophocarpus, a small African-Madagascan legume genus in Fabaceae tribe Phaseoleae, is known for the winged bean P. tetragonolobus, a protein-rich multipurpose tropical crop with four-winged, explosively dehiscent pods.
Psophocarpus tetragonolobus
Psophocarpus tetragonolobus, the winged bean or goa bean, is a twining tropical legume grown in hot, humid regions for its edible pods, seeds, leaves, and tubers.
Psoralea
Psoralea L. (fountainbush) is a Cape-centered legume genus in tribe Psoraleeae, described by Linnaeus in 1753, native Mozambique to South Africa, with about 129 species after absorbing Otholobium.
Psychotria
Psychotria L. (synonyms Cephaelis, Mapouria) is a pantropical genus of understory Rubiaceae shrubs with about 1,600-1,800 species, heterostylous flowers, red drupes, and bacterial leaf nodules; once broader, now split among Palicourea, Eumachia and others.
Psychotria viridis
Psychotria viridis (chacruna), a Rubiaceae shrub from Mexico to tropical South America, is the DMT-containing leaf ingredient of ayahuasca, containing 1–1.6 mg DMT per gram of dry leaf; often confused with the alkaloid-free P. carthagenensis.
Psyllium
Psyllium, also known as isabgol or ispaghula, is the gel-forming husk fiber of the plant Plantago ovata, used as a bulk laxative and to lower cholesterol.
Pteridaceae
Pteridaceae, the maidenhair fern family (syn. Adiantaceae, Vittariaceae, Parkeriaceae), is a monophyletic fern family of over 1000 species in five subfamilies (PPG I 2016), defined by pseudoindusia, trilete spores, and x = 29 or 30 chromosomes.
Pteridium
Pteridium (bracken, bracken fern), genus of Dennstaedtiaceae ferns; cosmopolitan, 20 accepted species, two diploid species P. aquilinum and P. esculentum; toxic, ptaquiloside carcinogen, IARC Group 2B, invasive weed.
Pteridium aquilinum
Pteridium aquilinum (bracken fern), Dennstaedtiaceae, is a rhizomatous fern native from Macaronesia and Africa to Siberia and Iran. It contains the carcinogen ptaquiloside, poisons livestock, and contaminates milk and water.
Pteridomania
Pteridomania, or fern fever, was the Victorian passion for collecting and growing ferns that swept Britain between 1837 and 1914, coined by Charles Kingsley in 1855.
Pteridophyte
Pteridophyte, informal term for free-sporing vascular plants, comprising lycophytes and ferns; spore reproduction, independent gametophyte and sporophyte; PPG I 2016 recognizes 11,916 species, 337 genera, 51 families, 14 orders, two classes.
Pteris
Pteris is a genus of brake ferns comprising 200 to 349 species across all continents except Antarctica. It is scientifically significant for its arsenic-hyperaccumulating species, Pteris vittata.
Pteris vittata
Pteris vittata, Chinese brake or ladder brake fern (Pteridaceae), first discovered natural arsenic hyperaccumulator, native to the Old World tropics, used for phytoremediation of arsenic-contaminated soils and groundwater.
Pterocarpus
Pterocarpus (padouk, narra, red sanders) is a pantropical legume tree genus in Fabaceae, tribe Dalbergieae, with winged indehiscent pods and red resin; prized timbers include P. indicus, P. soyauxii, and endangered P. santalinus.
Pterocarpus macrocarpus
Pterocarpus macrocarpus, Burma padauk, pradoo, thnong: a deciduous Fabaceae timber tree native to Indochina, 10-30 m tall, with red termite-resistant heartwood, winged pods, and EU Annex D trade controls.
Pterocarpus santalinus
Pterocarpus santalinus (red sandalwood, red sanders) is an Endangered Fabaceae tree endemic to southern India's Eastern Ghats, CITES Appendix II since 1995, yielding claret-red heartwood and the dye santalin for furniture, medicine, and instruments.
Pterocarya
Pterocarya (wingnuts), genus of six Juglandaceae tree species native from Türkiye and Iran to East Asia; Cenozoic relict with Caucasus–East Asia disjunction, winged nutlets in pendulous catkins, and Miocene divergence from Juglans.