Plants and algae

Trachycarpus fortunei

Trachycarpus fortunei, the Chinese windmill palm or Chusan palm, is a cold-hardy dioecious fan palm native to south-central China and northern Myanmar, widely grown as an ornamental and invasive in southern Switzerland.

Trachyspermum

Trachyspermum (ajwain, Trachyspermum ammi) is a genus of Apiaceae herbs, published by Link in 1821, native from NE Africa to Central Asia; 15 accepted species, polyphyletic, seeds used as spice and medicine.

Tradescantia

Tradescantia (spiderworts), a New World genus of about 90 herbaceous species in Commelinaceae, order Commelinales; includes wandering Jew (T. zebrina), inch plant, and oyster plant (T. spathacea), with Rhoeo, Zebrina, and Setcreasea as synonyms.

Tradescantia ohiensis

Tradescantia ohiensis, Ohio spiderwort, smooth spiderwort, or bluejacket: a clump-forming Commelinaceae perennial native from Ontario to the central and eastern United States, with blue to rose three-petaled one-day flowers, 18 synonyms, and NatureServe rank G5.

Tradescantia pallida

Tradescantia pallida (purple heart, purple queen) is a Mexican trailing Commelinaceae perennial with deep purple leaves and pink morning-opening flowers, mildly irritant sap, easy stem-cutting propagation, and invasive status in parts of South Africa and Italy.

Tradescantia zebrina

Tradescantia zebrina, the zebra plant or inch plant (formerly Zebrina pendula), is a trailing Commelinaceae houseplant native from Mexico to Colombia, with silver-striped purple leaves, easy propagation, and invasive status in Florida, Brazil, and South Africa.

Tragopogon

Tragopogon is a genus of about 130 daisy-family herbs native to temperate Eurasia, the Canary Islands, and North Africa, known for salsify and dandelion-like wind-dispersed fruits.

Tragopogon porrifolius

Tragopogon porrifolius, salsify or oyster plant (Tragopogon sativus), a purple-flowered biennial Asteraceae native from the Canary Islands to the Arabian Peninsula, grown for its oyster-flavored taproot and naturalized widely as a mild weed.

Trapa

Trapa (water caltrop, water chestnut) is a genus of annual floating-leaved aquatic plants in Lythraceae, native to the Old World, with 8 accepted species, starchy edible horned fruits, and invasive populations in North America.

Tree

Tree: a perennial woody plant with a single trunk and crown, defined variously as at least 2 m (FAO) to over 6 m tall. Covers wood, xylem transport, tree rings, forest extent (4.14 billion ha), and deforestation.

Tree fern

Tree ferns are ferns, mostly in the order Cyatheales (~600 species, 7–8 families), that grow trunk-like upright rhizomes mantled in adventitious roots rather than wood; Cyatheaceae holds ~90% of species, with Gondwanan origins and CITES Appendix II trade regulation.

Tree fern cultivation

Tree fern cultivation is the horticulture of arborescent ferns, grown for their fibrous trunks and crowns of large fronds, with care centered on the trunk and crown.

Tree fern cultivation: Dicksonia and Dicksoniaceae in horticulture

Tree fern cultivation in temperate gardens centers on Dicksonia antarctica, the soft tree fern, sold as harvested trunk logs that regrow fronds and need daily watering and winter crown protection.

Tree fern forest ecology

Tree fern forest ecology is the study of forests where tree ferns dominate, as in New Zealand and Australia, where they filter seedlings, host epiphytes, and colonize after disturbance.

Tree line

Treeline (tree line): the elevation or latitude beyond which climate is too cold for trees, defined as the line connecting uppermost trees >3 m. Set by growing-season temperatures (6.4 °C mean, 94 days), it shifted upslope 0.40 m/yr from 1901–2021, lagging warming by 50+ years.

Tree of 40 Fruit

Tree of 40 Fruit: series of grafted living sculptures by Sam Van Aken of Syracuse University, each bearing up to 40 stone-fruit varieties (plums, peaches, apricots, nectarines, cherries, almonds); first tree, Tree 75, dedicated 2011 on the Syracuse campus.

Trees of India

Trees of India: the country's tree species and tree cover, 827,357 sq km (25.17% of land) per ISFR 2023, in 16 forest type groups from Western Ghats evergreen to Himalayan pine and thorn forests.

Trema

Trema Lour. is a pantropical genus of pioneer trees and shrubs in Cannabaceae, published in 1790, with about 20 species (including Parasponia), 3-veined serrate leaves, and small hard-endocarp drupes.

Triadica

Triadica Lour. (Euphorbiaceae), a three-species Asian tree genus including Chinese tallow (Triadica sebifera), source of vegetable tallow and stillingia oil and invasive in the southeastern United States.

Triassic–Jurassic fern spore abnormalities

Triassic–Jurassic fern spore abnormalities are malformed fossil spores, up to 70% in some samples, marking environmental stress at the end-Triassic extinction about 201.6 million years ago.

Tribulus cistoides

Tribulus cistoides, Jamaican feverplant or puncture vine, is a prostrate Zygophyllaceae herb native from Cape Verde and Eritrea to Mozambique and the Pacific, with large yellow flowers and spiny burr fruits, used as medicine and food.

Tribulus terrestris

Tribulus terrestris, or puncture vine, is a spiny-fruited herb used in traditional Chinese and Indian medicine and sold as a supplement, though trials show it does not raise testosterone.

Trichomanes

Trichomanes is a mainly Neotropical genus of filmy ferns (Hymenophyllaceae), type T. crispum, published 1753, with tubular sori, chromosome base number x = 32, and a narrow modern circumscription after molecular splitting of Trichomanes s.l. into eight genera.

Trichome

Trichome: hair-like epidermal outgrowth on aerial plant parts, also called plant hairs; glandular or non-glandular, unicellular or multicellular. Found on most terrestrial plants; defend against herbivores and UV, and glandular types make essential oils and artemisinin.

Tridactyle

Tridactyle Schltr. is a genus of about 52 accepted African angraecoid orchids (Orchidaceae, Vandeae, Angraecinae), epiphytic monopodial herbs with three-lobed, spurred lips, native to tropical and southern Africa.

Tridax

Tridax (coat buttons, tridax daisy) is a genus of about 25-30 Asteraceae herbs native from Mexico to tropical America, published by Linnaeus in 1753; its type species Tridax procumbens is a pantropical weed used in traditional medicine.

Tridax procumbens

Tridax procumbens (coat buttons, tridax daisy, ghamra) is a creeping Asteraceae herb native to Mexico and tropical America, now a pantropical invasive weed of roadsides and waste ground, used traditionally as a hair tonic and wound remedy.

Trifoliate orange (枳)

Trifoliate orange (枳, karatachi), Citrus trifoliata, formerly Poncirus trifoliata, is a deciduous thorny Chinese citrus relative, the hardiest citrus, used worldwide as a cold-hardy, disease-tolerant semi-dwarfing rootstock and in citrus hybrid breeding.

Trifolium alexandrinum

Trifolium alexandrinum, known as berseem or Egyptian clover, is an annual forage legume grown as a winter feed crop in the Nile Valley and northern India.