4,295 articles
Hawthorne and His Mosses
"Hawthorne and His Mosses" is Herman Melville's 1850 two-part review of Hawthorne's Mosses from an Old Manse, published pseudonymously in the Literary World; it praised Hawthorne's "great power of blackness" and shaped Melville's reputation.
Hazel
Corylus avellana, common hazel or European hazelnut, a Betulaceae shrub native to Europe and western Asia; wind-pollinated, self-sterile, source of the hazelnut crop dominated by Türkiye, distinct from Corylus maxima and americana.
Hazelnut
Hazelnut (fandoq), the nut of Corylus avellana: winter-flowering, wind-pollinated, self-incompatible; Turkey grows over 65% of the ~1.08 million-ton world crop, Italy second, Oregon 99% of US output; eastern filbert blight drives breeding.
Heart of palm
Heart of palm (palmito) is the edible apical bud of certain palms, mainly the clumping peach palm (Bactris gasipaes), sold canned or jarred; Costa Rica leads exports, and harvesting kills single-stem palms but not peach palm clumps.
Hechtia
Hechtia is a genus of rosette-forming, drought-adapted bromeliads established by Klotzsch in 1835, centered in Mexico and numbering about 92 species, many described since 2007.
Hedera
Hedera (ivy), including English ivy Hedera helix, is a genus of evergreen root-climbing woody vines in Araliaceae, native from Europe to Iran, flowering September to November, valued for wildlife and ornament but invasive in parts of North America, Australia, and New Zealand.
Hedera helix
Hedera helix, English or common ivy, is an evergreen woody climber (Araliaceae) native to Europe and temperate Asia, with lobed juvenile and unlobed flowering adult growth phases; invasive in North America, Australia, and New Zealand.
Hedwigiales
Hedwigiales (synonym Helicophyllales) is an order of acrocarpous mosses in Bryidae containing Hedwigiaceae, Rhacocarpaceae, and Helicophyllaceae, placed sister to Bartramiales at the base of the Bryidae.
Hedychium
Hedychium (garland-lily, ginger-lily) is a genus of 86 accepted rhizomatous Zingiberaceae species native to Madagascar and tropical and subtropical Asia; best-known species include white ginger (H. coronarium) and Kahili ginger (H. gardnerianum).
Hedyotis
Hedyotis L. is a Rubiaceae (coffee family) genus of herbs and subshrubs, published by Linnaeus in 1753, native to tropical and subtropical Asia to the NW Pacific, with type species H. fruticosa and a long-debated Hedyotis-Oldenlandia complex now split into many genera.
Hedysarum
Hedysarum (sulla, sweetvetch) is a genus of about 227 legume species in Fabaceae, tribe Hedysareae, with lomented pods, native to temperate Eurasia, North Africa, and western North America, divided into sections Hedysarum, Multicaulia, and Stracheya.
Heirloom plant
Heirloom plant: an open-pollinated cultivar, typically 50 to several hundred years old, whose seed is saved and passed down through generations. Comes true from seed, unlike F1 hybrids; valued for flavor, heritage, and crop diversity.
Heirloom tomato
Heirloom tomato, an open-pollinated tomato variety passed down 50+ years or introduced commercially before 1940; saved seed grows true to type, unlike hybrids; valued for flavor and color, with lower yields and disease resistance.
Heliamphora
Heliamphora (sun pitchers, marsh pitchers) is a genus of about 21 to 24 carnivorous Sarraceniaceae pitcher plants endemic to the tepuis of Venezuela, Guyana, and northern Brazil, with pitfall traps, nectar spoons, and confirmed endogenous digestive enzymes.
Helianthemum
Helianthemum (rock rose, sun rose) is the largest genus of Cistaceae, about 140 Palearctic taxa centered on the Mediterranean, with three radiating sections since the Late Miocene and hard-coated seeds needing scarification.
Helianthus
Helianthus (sunflowers) is a North American Asteraceae genus of 56 accepted species, including cultivated sunflower (H. annuus) and Jerusalem artichoke (H. tuberosus); domesticated ~4,000-5,000 years ago and a model for hybrid speciation.
Helichrysum
Helichrysum (everlasting flowers) is a genus of about 564 accepted Asteraceae species native from Europe and Africa to Australia, widely used in traditional medicine; H. italicum yields a commercially important essential oil.
Heliconia
Heliconia (lobster-claw, false bird-of-paradise) is the sole genus of Heliconiaceae in Zingiberales, tropical herbs with colorful bracts pollinated by hummingbirds; about 187 species from Mexico to tropical America and the Pacific, nearly half threatened.
Heliconia bihai
Heliconia bihai (macawflower, lobster claw) is a large rhizomatous Heliconiaceae herb native to Mexico, the Caribbean, and northern South America, hummingbird-pollinated, polymorphic in bract color, and cultivated as an ornamental, food, and medicine.
Helictotrichon
Helictotrichon (oat grasses), Poaceae genus published 1827 by Besser ex Schultes & Schult.f.; about 30 accepted species of temperate perennial grasses, narrowed by molecular work, including ornamental blue oat grass H. sempervirens.
Heliotropium
Heliotropium (heliotrope), a genus of about 250 species in Heliotropiaceae (Boraginales) established by Linnaeus in 1753; cosmopolitan herbs and shrubs with scorpioid cymes, pyrrolizidine alkaloids, and C4 species in section Orthostachys.
Heliotropium arborescens
Heliotropium arborescens, garden heliotrope or cherry pie plant (syn. H. peruvianum), is a Boraginaceae subshrub native to Bolivia, Colombia, and Peru, grown for vanilla-scented purple flowers; toxic via pyrrolizidine alkaloids.
Hellebore
Hellebore (Helleborus), also called Christmas rose or Lenten rose, is a genus of about 15 poisonous Ranunculaceae perennials native from Europe to N. China, flowering in late winter and spring, once famed in ancient Greek medicine as a cure for madness.
Helleborus
Helleborus, the hellebores, a genus of about 15-22 poisonous perennial species in Ranunculaceae native from Europe to the Caucasus, NW Africa, and N China; includes the Christmas rose H. niger and Lenten rose H. × hybridus.
Helleborus niger
Helleborus niger, the Christmas rose or black hellebore, is a poisonous Ranunculaceae perennial native to the Alps and Apennines, blooming white December to March, with cardiotonic helleborin and two subspecies, niger and macranthus.
Hemicellulose
Hemicellulose is a group of branched, non-cellulosic polysaccharides in plant cell walls that bind to cellulose and reinforce it, making up 20 to 35% of the wall and including xylans and xyloglucans.
Hemlock woolly adelgid
Hemlock woolly adelgid (Adelges tsugae), a Japanese sap-sucking insect invasive in eastern North America since about 1951, kills eastern and Carolina hemlocks; spread rates, ecology, and chemical and biological control.
Hemp oil
Hemp oil (hemp seed oil) is the culinary oil pressed from Cannabis sativa seeds, naturally free of THC and CBD, GRAS-recognized by FDA in 2018, and distinct from hemp-derived CBD oil extracted from flowers and leaves.
Heracleum (plant)
Heracleum, commonly known as hogweed or cow parsnip, is a genus of about 90 herbs in the carrot family native to the temperate Northern Hemisphere, some reaching 18 ft.
Heracleum mantegazzianum
Heracleum mantegazzianum, giant hogweed, is a 5 m tall monocarpic Apiaceae herb native to the Western Greater Caucasus, invasive in Europe and North America, whose furanocoumarin sap causes phototoxic dermatitis.