Plants and algae

Houstonia caerulea

Houstonia caerulea, the azure bluet or Quaker ladies, is a small wildflower of the madder family native to eastern North America, with pale blue, four-lobed spring flowers.

Houttuynia cordata (chameleon plant, fish mint, yu xing cao) is an Asian Saururaceae herb eaten as a vegetable, used in traditional Chinese medicine, studied for anti-inflammatory and antiviral effects, and invasive outside its native range.

Huabancai

Huabancai (滑板菜) is a wild mountain vegetable from the climbing perennial vine Parabaena sagittata, typically stir-fried or cooked with meat in Xishuangbanna, Yunnan, where dwindling wild supplies prompted a patented cutting-propagation method.

Huangge Rong

黄葛榕 (Ficus virens, also 黄葛树/黄桷树/大叶榕) is a large deciduous fig of Moraceae native to south and southwest China; Chongqing's city tree and namesake of Huangguoshu Waterfall.

Huckleberry

Huckleberry is a common name for berries of two Ericaceae genera: Gaylussacia (true eastern huckleberries, 10 hard seeds) and western Vaccinium species such as Vaccinium membranaceum, the commercially important Pacific Northwest black huckleberry.

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.

Huoshaohua

火烧花 (Mayodendron igneum), also 缅木, is a Bignoniaceae evergreen tree from southern China and Indochina; its orange-yellow flowers bloom on the old trunk (cauliflory) and are eaten as a Xishuangbanna vegetable. Distinct from Spathodea campanulata, which shares the name.

Huperzia

Huperzia (firmoss) is a genus of terrestrial clubmosses in Lycopodiaceae, named for Johann Peter Huperz; reproduces by gemmae, lacks strobili, and is the source of the Alzheimer's drug huperzine A.

Huperzine A

Huperzine A, a Lycopodium alkaloid from Huperzia serrata (Qian Ceng Ta), is a reversible acetylcholinesterase inhibitor studied for Alzheimer's disease; sold as a US supplement, a drug in China, with insufficient clinical evidence.

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.

Hushpuppy

Hushpuppy: small deep-fried balls of seasoned cornmeal batter, a Southern US side dish served with fried fish, seafood, and barbecue; name traced to Carolinas and Georgia fish fries, with dog-feeding origin stories.

Husk

Husk: the dry outer covering of seeds, grains, or fruits (also hull, chaff); in maize, modified leaves protecting the ear, photosynthesizing, and enabling kernel drydown; from late 14c. English huske.

Hyacinth

Hyacinthus (hyacinth) is a small Asparagaceae bulb genus from southern Türkiye to northern Israel and southern Turkmenistan, with three accepted species; the garden hyacinth derives entirely from Hyacinthus orientalis, though molecular work makes the genus polyphyletic.

Hyacinthoides non-scripta

Hyacinthoides non-scripta, the English or common bluebell, is a bulbous Asparagaceae geophyte native to western Europe, with scented one-sided violet-blue spring flowers; UK-protected, threatened by hybridization with H. hispanica.

Hyacinthus orientalis

Hyacinthus orientalis, common or Dutch hyacinth, a bulbous geophyte native from southern Türkiye to northern Israel, source of all garden hyacinth cultivars; fragrant spring spikes, Dutch bulb trade history, forcing culture, mildly toxic bulbs.

Hybrid (biology)

Hybrid (biology): offspring of genetically distinct parents, often different species. Plant hybrids show sterility or inviability, drive speciation via polyploidy or introgression, and power heterosis in hybrid crops.

Hybrid larch

Hybrid larch, also called Dunkeld larch, is the hybrid of European larch and Japanese larch, first recognized at Dunkeld, Scotland, in 1905 and grown for timber because it outgrows both parents.

Hybrid maize

Hybrid maize is corn produced by crossing two genetically distinct inbred parent lines; first published in 1908, it spread across nearly all US corn acreage by 1960.

Hybrid rice

Hybrid rice: F1 rice from crosses of distinct parents exploiting heterosis, developed in China from Yuan Longping's 1960 work; three-line CMS, two-line EGMS, and third-generation GMS systems cover about half of China's rice area.

Hybrid tea rose

The hybrid tea rose is a class of modern garden rose bred from tea roses and hybrid perpetuals, the classic long-stemmed rose of florists and cutting gardens.

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.

Hydrangea

Hydrangea, a genus of shrubs and climbers including H. macrophylla, arborescens, paniculata, and quercifolia; pH-sensitive flower color, old-wood versus new-wood pruning, and RHS trial results.

Hydrangea macrophylla (紫陽花)

Hydrangea macrophylla (紫陽花), bigleaf or French hydrangea, a Japanese deciduous shrub with mophead or lacecap flower heads; blue in acidic soil, pink in alkaline, blooming on old wood with reblooming cultivars like Endless Summer.

Hydrilla

Hydrilla (Hydrilla verticillata), or waterthyme, is an invasive submerged aquatic plant of Hydrocharitaceae with whorled serrated leaves, tubers, and turions; introduced via the aquarium trade, it infests 28 US states and is a Federal Noxious Weed.

Hydrocharitaceae

Hydrocharitaceae, the frog's-bit or tape-grass family (Najadaceae synonym), is a cosmopolitan family of 14 genera and about 136 fully aquatic monocot herbs in Alismatales, with 3 marine seagrass genera, water pollination, and an Asian Late Cretaceous origin.