3,306 articles
Urtica dioica
Urtica dioica, stinging nettle, common nettle: a dioecious rhizomatous perennial herb of Urticaceae native from Europe to Siberia and NW Africa, with silica-mineralized stinging hairs injecting histamine and acetylcholine, used as food, fiber, and herbal medicine.
Urtica urens
Urtica urens, the small or burning nettle, is an annual stinging herb up to 60 cm tall, native to the Old World and now almost cosmopolitan.
Urticaceae
Urticaceae, the nettle family (order Rosales), is a family of about 59 genera and roughly 2,100 to 2,600 species of herbs, shrubs, and trees, often with stinging hairs and cystoliths; includes Urtica, Boehmeria, Pilea, Elatostema, and the former Cecropiaceae.
Utricularia
Utricularia (bladderworts), largest carnivorous plant genus with 288 accepted species in Lentibulariaceae; rootless plants with millisecond suction bladder traps, cosmopolitan distribution, and dynamic 60-1500 Mb genomes.
Uvaria
Uvaria is a genus of about 170 accepted species of climbing or trailing shrubs in the custard-apple family Annonaceae, native to the tropical and subtropical Old World to Australia, used in traditional medicine and revised phylogenetically to absorb several former genera.
Vaccinium
Vaccinium L. is a cosmopolitan genus of about 450–500 berry-bearing shrubs in Ericaceae, tribe Vaccinieae, including blueberry, cranberry, and lingonberry; type species V. uliginosum, known to be polyphyletic.
Vaccinium angustifolium
Vaccinium angustifolium, the lowbush or wild blueberry, is a tetraploid Ericaceae subshrub native to eastern North America, harvested from managed wild stands in Maine and Atlantic Canada on a two-year prune-crop cycle, with higher anthocyanins than highbush blueberry.
Vaccinium macrocarpon
Vaccinium macrocarpon, American or large cranberry, Oxycoccus macrocarpus, a diploid Ericaceae vine native to eastern North American bogs, domesticated from 1810, USDA breeding from 1929, Wisconsin grows about 60 percent of the U.S. crop.
Vaccinium myrtillus
Vaccinium myrtillus, bilberry or European blueberry, is a wild Ericaceae subshrub of Eurasia and North America with anthocyanin-rich berries; rigorous trials do not support its night-vision and most supplement health claims.
Vaccinium vitis-idaea
Vaccinium vitis-idaea, lingonberry or cowberry, a circumpolar evergreen Ericaceae subshrub 5-15 cm tall with red 8-10 mm tart berries; two subspecies, ssp. minus in North America, ssp. vitis-idaea in Eurasia; IUCN least concern.
Vachellia
Vachellia is a pantropical genus of about 164 species of spiny trees and shrubs in the legume family, holding most former Acacia species outside Australia.
Vachellia nilotica
Vachellia nilotica, also called babul, prickly acacia, or Egyptian acacia (formerly Acacia nilotica), is a leguminous African-Asian tree used for medicine, gum, fodder, and tanning; its subspecies indica is a Weed of National Significance in Australia.
Valerian (herb)
Valerian (Valeriana officinalis), also called all-heal or garden heliotrope, is a European and Asian perennial whose roots are used as a herbal sedative for sleep and mild nervous tension, though clinical evidence of efficacy is inconsistent.
Valeriana locusta
Valeriana locusta L., also called Valerianella locusta, corn salad or lamb's-lettuce, is a small annual Caprifoliaceae herb native from Europe to the Caucasus and NW Africa, naturalized in North America and Asia, with tiny bluish flowers and corky-backed fruit.
Valerianella
Valerianella, commonly called cornsalad, is a genus of about 50 to 65 annual herb species in the family Caprifoliaceae, native to temperate regions of the northern hemisphere.
Vallisneria
Vallisneria (tapegrass, eelgrass, wild celery) is a genus of dioecious submerged freshwater herbs in Hydrocharitaceae, pollinated at the water surface; 18 accepted species, center of diversity in Australia, widely used in aquariums and restoration.
Vanda
Vanda R.Br. is a genus of about 90 monopodial orchid species native from tropical Asia to the NW Pacific; among the five most horticulturally important orchid genera, source of Singapore's national flower Vanda Miss Joaquim.
Vanilla
Vanilla, flavoring from cured pods of the orchid Vanilla planifolia (95% of trade). Hand-pollinated since Edmond Albius's 1841 method; Madagascar grows ~80%; most vanillin consumed is synthetic.
Vanilla (genus)
Vanilla is a genus of climbing orchids whose fermented seed pods are the source of natural vanilla flavor, with about 129 species native to the tropics.
Vanilla planifolia
Vanilla planifolia (flat-leaved or Bourbon vanilla) is a climbing orchid native from southern Mexico to northern Brazil, source of 95% of traded vanilla; hand-pollinated since 1841, IUCN Endangered in the wild, grown mainly in Madagascar.
Vanilla pompona
Vanilla pompona (vanillon) is a Neotropical vanilla orchid, native from southern Mexico to southern tropical America, whose pods are rich in 4-methoxybenzyl alcohol rather than vanillin, unlike commercial V. planifolia.
Variegated aroids
Variegated aroids are cultivated arum family plants, including Monstera, Philodendron, and Alocasia, whose leaves carry white, cream, or yellow areas from chimeral or genetic change.
Variegation
Variegation, patchy leaf coloration in over 1,700 plant species, arises from chlorophyll deficiency, air spaces, epidermal structure, or pigment masking; caused by chimerism, transposons, plastid or mitochondrial mutations, and valued in ornamental horticulture.
Vatica
Vatica (resak) is a genus of about 65 to 80 Dipterocarpaceae trees from Sri Lanka and India to New Guinea, with 79 accepted Kew species, fragrant 5-merous flowers, and timber traded as resak.
Vegetable oil
Vegetable oil: triglyceride liquid from plant seeds, nuts, or fruits (palm, soybean, canola, sunflower, olive). Refined for food, biofuels, lubricants; oxidation limits shelf life.
Vegetative reproduction
Vegetative reproduction (vegetative propagation): asexual plant reproduction from stems, roots, or leaves producing clones. Methods include stolons, rhizomes, tubers, bulbs, cuttings, grafting, layering, and micropropagation; used for potato, sugar cane, tulips, and fruit trees.
Velamen
Velamen (velamen radicum): multilayered sheath of dead cells on orchid and some aroid aerial roots, absorbing water by imbibition, storing it, housing fungi; named by Link (1824) and Schleiden (1842).
Venus flytrap
Venus flytrap (Dionaea muscipula), a carnivorous snap-trap plant native only to North and South Carolina wetlands; traps close in about one-tenth of a second after trigger hairs are touched twice, and the species was ruled not warranted for ESA listing in 2023.
Veratrum
Veratrum (false hellebore, corn lily) is a genus of toxic perennial herbs in Melanthiaceae, tribe Melanthieae, conserved against Melanthium. About 17-45 species, mainly East Asian, contain steroidal alkaloids such as veratridine, jervine, and cyclopamine that open sodium channels, causing vomiting, bradycardia, and hypotension.
Veratrum album
Veratrum album (white hellebore), a toxic Melanthiaceae herb native from Europe to the N. Russian Far East; steroidal alkaloids cause bradycardia and hypotension; long medicinal history.