881 articles
Hippophae rhamnoides
Hippophae rhamnoides, sea buckthorn (Elaeagnaceae), a hardy nitrogen-fixing Eurasian shrub with seven subspecies, orange vitamin-rich berries used in food and traditional medicine, and limited clinical evidence of benefit.
History of cannabis
History of cannabis (Cannabis sativa): Eurasian domestication for fiber, food, and medicine; earliest psychoactive use at Jirzankal Cemetery; O'Shaughnessy's 19th-century medical promotion; 1925 Geneva control, 1937 US Marijuana Tax Act, and modern legalization.
Holodiscus discolor
Holodiscus discolor, oceanspray or creambush (Rosaceae), a deciduous arching shrub native from British Columbia to Mexico, with creamy white flower sprays, four varieties, fire-adapted, valuable to native bees.
Honey locust
Honey locust (Gleditsia triacanthos), also called sweet-locust or thorny-locust, is a thorned North American legume tree with sweet pods, thornless urban cultivars, and invasive populations in Argentina, Europe, and Australia.
Hops
Hops, the female cones of Humulus lupulus (Cannabaceae), are the brewing crop that bitters, flavors, and preserves beer via alpha acids and essential oils; cultivated since the 8th-century Hallertau, with over 260 varieties and medicinal uses.
Hornbeam
Hornbeam (Carpinus), a birch-family hardwood genus of about 19-40 Northern hemisphere species; European hornbeam (C. betulus) is a 25 m coppice and hedging tree of heavy lowland soils, with very hard wood used for cogs and mallets.
Horseradish
Horseradish (Armoracia rusticana), a Brassicaceae perennial from southeastern Europe and western Asia, grown over 3,000 years for its pungent taproot; allyl isothiocyanate from sinigrin gives the heat, and it substitutes for wasabi.
Humulus
Humulus (hops genus) is a Cannabaceae genus of dioecious twining herbs native to the temperate Northern Hemisphere, with 7 accepted species; H. lupulus cones supply beer bitterness, aroma, and preservation.
Humulus lupulus
Humulus lupulus, common hop, is a dioecious perennial Cannabaceae vine whose female cones (strobili) supply beer's bitterness and aroma; ~97% of production goes to brewing, with humulone, xanthohumol, and 8-prenylnaringenin as key compounds.
Hura crepitans
Hura crepitans, the sandbox tree or jabillo, is a spiny Euphorbiaceae tree native to tropical America with toxic sap and explosive fruit capsules that launch seeds at about 43 m/s up to 45 m.
Hydnocarpus kurzii
Hydnocarpus kurzii, commonly called chaulmoogra, is a dioecious evergreen tree native from Assam to Peninsular Malaysia whose seed oil was a standard historical treatment for leprosy.
Hymenaea courbaril
Hymenaea courbaril (jatobá, West Indian locust) is a 30-50 m Neotropical legume tree from Mexico to southeastern Brazil, yielding copal resin, dense timber, and starchy edible pod pulp; formerly six varieties, split into three species in 2014.
Hypericaceae
Hypericaceae, the St. John's wort family (Hypericaceae Juss., 1789), is a Malpighiales family of herbs and shrubs with gland-dotted leaves; its dominant genus Hypericum holds 521 species, and sister family is Podostemaceae.
Hypericum
Hypericum (St. John's worts), genus of Hypericaceae with about 500 yellow-flowered species of herbs and shrubs, cosmopolitan mainly in temperate regions; includes medicinal H. perforatum and invasive weeds.
Hypericum perforatum
Hypericum perforatum (St. John's wort, Klamath weed) is a perennial Hypericaceae herb native from Europe to China and NW Africa, used for mild to moderate depression; extracts show efficacy near standard antidepressants but induce CYP3A4 and P-glycoprotein, causing major drug interactions.
Indian hemp
Indian hemp, also called kenaf, Deccan hemp, or Java jute (Hibiscus cannabinus L.), is an African-originated annual Malvaceae fiber crop grown for cordage, paper pulp, and biocomposites, unrelated to Cannabis sativa.
Indigofera
Indigofera (indigo plants), a Fabaceae legume genus of 764 species, pantropical with Africa-Madagascar as its diversity center; source of the blue dye indigo via Indigofera tinctoria and I. suffruticosa, also used as forage, medicine, and green manure, with some species toxic to livestock.
Indigofera tinctoria
Indigofera tinctoria (true indigo, nila) is a Fabaceae shrub whose indican-rich leaves yield indigo dye; native range spans tropical Africa and South Asia, displaced commercially by synthetic indigo after 1897.
Inga
Inga is a genus of about 300 species of nitrogen-fixing trees in the legume family Fabaceae, native to tropical America and long grown as shade for coffee and cacao.
Isatis tinctoria
Isatis tinctoria (woad, dyer's woad, pastel) is a Brassicaceae biennial native from SE and E Europe to Türkiye, the historical European source of indigo dye via precursors indican and isatan B, displaced by tropical indigo and synthetic indigo.
Jabuticaba
Jabuticaba (jaboticaba, Brazilian grape tree, Plinia cauliflora) is a slow-growing Myrtaceae fruit tree from Brazil whose dark purple berries and white flowers grow directly on the trunk (cauliflory); grown in zones 9a-11, fruiting in 8-10 years from seed.
Jatropha
Jatropha, a Euphorbiaceae genus of about 150 tropical species including the physic nut (Jatropha curcas), a toxic-seeded oil crop promoted for biodiesel whose large plantations proved barely financially viable.
Jatropha curcas
Jatropha curcas, physic nut or piñón de purga, a toxic Euphorbiaceae shrub native from Mexico to tropical America, grown as hedges and promoted as a biodiesel feedstock; seeds contain phorbol esters and curcin, making the oil non-edible.
Jaya Sri Maha Bodhi (ජය ශ්රී මහා බෝධි)
Jaya Sri Maha Bodhi (ජය ශ්රී මහා බෝධි) is the sacred fig tree in Anuradhapura, Sri Lanka, planted in 288 BC by Sanghamitta from the original Bodhi tree; the oldest human-planted tree with a known planting date.
Juglandaceae
Juglandaceae, the walnut family (DC. ex Perleb, 1818), is a Fagales family of trees including Juglans, Carya, Pterocarya, and Rhoiptelea, with compound leaves, catkins, and one-seeded nuts, source of walnuts, pecans, and valuable timber.
Juglans
Juglans, the walnut genus of Juglandaceae, has 21 accepted species including J. regia, J. nigra, and J. cinerea, native from the Americas to East Asia; threatened by thousand cankers disease and butternut canker.
Juglans nigra
Juglans nigra, black walnut or American walnut, is an eastern North American hardwood tree prized for dark chocolate-brown, dimensionally stable, decay-resistant timber used in furniture, veneer, and gunstocks, with edible nuts and disputed juglone allelopathy.
Juglans regia
Juglans regia, Persian or common walnut, a Juglandaceae tree native from Türkiye to the west Himalaya, anciently hybrid-origin, spread across Europe by humans since the Bronze Age for nuts and timber.
Jujube
Jujube (Ziziphus jujuba, Chinese date, red date, 枣) is a temperate Rhamnaceae fruit tree native to China and Korea, domesticated from wild sour jujube over 7,000 years ago; distinct from Indian jujube Z. mauritiana, with ~2 million hectares grown in China.
Kalanchoe
Kalanchoe (mother of thousands, flaming katy) is a genus of about 167–176 succulent Crassulaceae species, mostly Malagasy, with CAM photosynthesis, bufadienolide toxicity to pets, major horticultural use, and invasive escapes worldwide.