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Ulmus glabra 'Camperdownii'
Ulmus glabra 'Camperdownii', the Camperdown elm or weeping elm, a weeping wych elm cultivar found mid-1800s at Camperdown House, Dundee, Scotland; propagated only by grafting, small, hardy to USDA Zone 4, susceptible to Dutch elm disease.
Ulmus glabra 'Lutescens'
Ulmus glabra 'Lutescens', the Golden Elm or Golden Wych Elm, is a wych elm cultivar found near York in the early 19th century, grown for cream-yellow spring leaves turning golden in autumn, reaching 10-12 m, popular in Australia.
Ulmus minor
Ulmus minor, field elm or smooth-leaved elm (olmo), a deciduous Ulmaceae tree native from Europe to Central Asia and NW. Africa; riparian pioneer to 20 m, devastated by Dutch elm disease (Ophiostoma), IUCN Data Deficient, with two accepted subspecies.
Ulmus pumila
Ulmus pumila, the Siberian elm (also called littleleaf, dwarf, or Chinese elm), is a fast-growing, drought- and frost-hardy Asian elm, resistant to Dutch elm disease, used in breeding and windbreaks, and invasive in North America.
Ulmus rubra
Ulmus rubra Muhl., slippery elm (also red elm, gray elm, soft elm), a medium-sized deciduous North American elm of Ulmaceae, named for mucilage in its inner bark used in throat lozenges; threatened by Dutch elm disease.
Ulva lactuca
Ulva lactuca (sea lettuce) is a green macroalga in Ulvaceae, type species of the genus Ulva, described by Linnaeus in 1753; thin two-layered edible blades, worldwide coastal distribution, used as food, feed, biofuel feedstock, and pollution bioindicator.
Umbilicus
Umbilicus (navelworts) is a genus of about 12 succulent Crassulaceae herbs with peltate, navel-marked basal leaves and urn-shaped flowers, native from Macaronesia and Europe to Iran, Arabia, and Tanzania.
Uncaria
Uncaria (gouteng, cat's claw) is a pantropical genus of about 38 climbing Rubiaceae lianas with claw-like hooks, rich in indole alkaloids and widely used in traditional medicine.
Uncaria gambir
Uncaria gambir (gambier, pale catechu) is a climbing Rubiaceae shrub native to western Malesia, cultivated in Indonesia and Malaysia; its leaf-and-twig extract is used for betel chewing, tanning, and traditional medicine.
Uncinia
Uncinia Pers., a former genus of about 70 hooked-rachilla sedges in tribe Cariceae (Cyperaceae), merged into Carex in 2015 as Carex subg. Uncinia; Southern Hemisphere, allopolyploid origin.
Understory
Understory: the forest vegetation layer beneath the canopy, including shrubs, herbs, ferns, and bryophytes; shaped by overstory light, buffers microclimate, drives regeneration, nutrient cycling, and carbon storage.
Universidad autonoma de yucatan herbarium
Herbario Alfredo Barrera Marín (UADY), herbarium of the Universidad Autónoma de Yucatán's veterinary faculty in Mérida, Mexico; founded 1989, Engler system, Yucatán, Campeche, and Quintana Roo flora, Etnoflora Yucatanense program.
Universita di perugia herbarium
Herbarium of the University of Perugia (Erbario, acronym PERU), Italy. Rooted in 16th-century botanical teaching and the 1720 garden, it includes Batelli's 15,000-sheet herbarium, the Cicioni exsiccata, and the PERU-m mycological collection.
Universita di venezia herbarium
Universita di Venezia herbarium (UVV), the herbarium of Ca' Foscari University of Venice at Campo Celestia, used for voucher specimens and anArchive botanical data; distinct from the city museum's MCVE herbarium.
University college of swansea herbarium
University College of Swansea herbarium (UCSA), Swansea University's dried plant collection; vascular plants donated in 2006 to National Museum Wales (4,256 specimens), bryophytes retained at Swansea.
Urena lobata
Urena lobata (Caesar's weed, Congo jute, aramina) is a pantropical Malvaceae subshrub grown for jute-like bast fiber, used medicinally, and invasive in Florida and the Philippines.
Urochloa
Urochloa (syn. Brachiaria) is a pantropical African-centred grass genus whose species, including U. brizantha, U. decumbens, U. humidicola, and U. ruziziensis, are major apomictic polyploid tropical pasture forages covering over 100 million hectares in Brazil.
Urochloa brizantha
Urochloa brizantha, long known as Brachiaria brizantha and commonly called palisade grass, is a perennial tropical forage grass native to Africa, widely cultivated as pasture, especially in Brazil.
Urtica
Urtica (nettles), genus of stinging-haired herbs in Urticaceae, Rosales, first published 1753; about 50-69 accepted species, subcosmopolitan except Antarctica; includes U. dioica and U. urens, used as food and medicine.
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.
Uses of haircap mosses
Haircap mosses (Polytrichaceae) are large mosses with internal water-conducting tissue, used historically for stuffing, cloaks, brooms, and folk medicine, and now grown as ornamental terrarium plants.
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.
Utricularia cultivars and hybrids
Utricularia cultivars and hybrids are named forms of the carnivorous bladderwort genus Utricularia, selected for traits like flower size and registered by the International Carnivorous Plant Society, with 16 cultivars recorded.
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 corymbosum
Vaccinium corymbosum, highbush blueberry (northern highbush), is a tetraploid Ericaceae shrub native to eastern North America, domesticated from 1908 by Coville and Elizabeth White at Whitesbog, New Jersey; it supplies about 90% of northern highbush cultivar ancestry and, crossed with V. darrowii, the southern highbush group.
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.