Plants

Sweet potato (Ipomoea batatas) Sweet potato Starchy, sweet-tasting root crop in the morning glory family, valued worldwide for food, nutrition and versatile culinary uses; includes varieties with orange, white, purple flesh…

Sweet William (Dianthus barbatus): a fragrant garden pink Sweet William Sweet William, Dianthus barbatus, is a biennial or short-lived perennial in the pink family, grown for dense clusters of fragrant red, pink and white flowers and valued in temperat…

Syringa vulgaris (common lilac) Syringa vulgaris Syringa vulgaris, the common lilac, is a deciduous ornamental shrub in the olive family valued for fragrant spring blooms. Native to the Balkans, it is widely cultivated and natura…

Syzygium — tropical genus of flowering trees and shrubs in Myrtaceae Syzygium Syzygium is a large genus of evergreen trees and shrubs in the myrtle family, with about 1,100 species native from Africa and Madagascar across southern Asia to the Pacific, many w…

Tabasco pepper (Capsicum frutescens variety) Tabasco pepper Small, pungent chili of the Capsicum frutescens species, famous as the ingredient in Tabasco sauce and used fresh, pickled, or fermented for hot sauces and condiments.

Tabebuia — trumpet trees of the Americas Tabebuia Tabebuia is a group of tropical American flowering trees in the family Bignoniaceae, noted for large trumpet-shaped blossoms, durable timber and ornamental use. Modern studies have…

Tagetes (marigolds): description, species, uses and cultivation Tagetes Tagetes, commonly called marigolds, is a genus of about 56 species in the Asteraceae family native to the Americas, valued for ornament, companion planting, cultural ceremonies, an…

Talipot palm (Corypha umbraculifera) Talipot palm Corypha umbraculifera, the talipot palm, is a giant fan palm of South and Southeast Asia, noted for enormous palmate leaves, the largest inflorescence of any plant, and a single te…

Tamarillo (tree tomato): description, origins, cultivation and uses Tamarillo Tamarillo (Solanum betaceum) is an egg‑shaped, tangy fruit from a small tree in the nightshade family, native to the Andes and grown in subtropical regions for fresh eating, sauces…

Tamarind (Tamarindus indica) Tamarind Tamarind is a tropical evergreen tree whose fruit yields a tart-sweet pulp used worldwide in cooking, medicine, and industry. Native to Africa, it has long been cultivated across A…

Tangelo — citrus hybrid fruit Tangelo A tangelo is a citrus hybrid with tangerine (mandarin) and grapefruit/pomelo ancestry; known for its sweet-tart flavor, loose skin and ease of peeling. Several cultivars, including…

Tangor — the tangerine × sweet orange hybrid Tangor Tangor is a citrus hybrid of tangerine and sweet orange, valued for fragrant, sweet flesh and thin peel. Used fresh, for juice, and in breeding; includes cultivars such as Temple,…

Taro (Colocasia esculenta): staple root crop and leaf vegetable Taro Taro is a tropical plant grown for its starchy corms and edible leaves. An early cultivated crop in Oceania and beyond, it is a dietary staple, used in many traditional dishes afte…

Tarragon (Artemisia dracunculus): culinary herb, varieties and cultivation Tarragon Tarragon (Artemisia dracunculus), commonly called estragon, is a fragrant perennial herb used in cooking and traditional remedies. Covers appearance, varieties, cultivation, uses a…

Tasmannia (Tasmanian pepper): evergreen shrubs and spice plants Tasmannia Tasmannia is a genus of evergreen woody plants from Australasia. Known for aromatic leaves, peppery berries and polygodial-based pungency, several species are used as condiments, e…

Tayberry — a blackberry–raspberry hybrid Tayberry Tayberry is a cultivated Rubus hybrid between blackberry and red raspberry, noted for large, aromatic fruit. Bred in Scotland and patented in 1979, it is prized by gardeners though…

Teak (Tectona grandis): timber, tree characteristics, uses and conservation Teak Teak (Tectona grandis) is a tropical hardwood tree valued for durable, oily timber used in boats, furniture and decking. Native to South and Southeast Asia, it is now grown widely…

Teasel (Dipsacus): description, ecology, uses and management Teasel Teasel (genus Dipsacus) are tall, biennial herbaceous plants with prickly stems and distinctive seed heads; native to Eurasia and North Africa, valued for wildlife and historic tex…

Tecophilaea — the Chilean blue crocus genus Tecophilaea Tecophilaea is a small genus of bulbous flowering plants in the family Tecophilaeaceae, noted for vivid blue, crocus-like blooms. Native to Chile, one species faces conservation co…

Tecophilaeaceae: a small family of cormous flowering plants Tecophilaeaceae Tecophilaeaceae is a small family of mainly Southern Hemisphere flowering plants in the Asparagales, characterized by corms, six‑tepal flowers and capsule fruits; some species are…

Teosinte: wild grasses of the genus Zea and the ancestor of maize Teosinte Teosintes are wild grasses in the genus Zea native to parts of Mesoamerica. They are the closest wild relatives of maize and are important for genetics, crop improvement, and biodi…

Tetragonia tetragonoides — New Zealand spinach Tetragonia tetragonoides Tetragonia tetragonoides, called New Zealand spinach or warrigal greens, is a succulent leafy plant in Aizoaceae grown as a heat‑tolerant summer vegetable, coastal groundcover and…

Thai basil: characteristics, culinary uses, and cultural context Thai basil Thai basil is a variety of sweet basil used across Southeast Asia. Recognizable by its narrow leaves, purple stems and anise-like scent, it’s prized in soups, curries and stir-frie…

Theobroma — tropical genus that includes the cacao tree Theobroma Theobroma is a small genus of tropical American trees whose seeds produce cocoa and chocolate. It includes cacao, cupuaçu and other species valued for food, culture and agroforestr…

Thistle: prickly flowering plants in the daisy family Thistle Thistles are spiny flowering plants in the Asteraceae (daisy) family. This article explains their appearance, classification, ecology, uses, and cultural significance, with example…

Thorns, spines and prickles: plant sharp structures and their roles Thorns, spines and prickles Clear explanation of the botanical differences between thorns, spines and prickles, their origins, functions, examples and ecological importance, with distinguishing features and u…

Threshing: separating cereal grain from chaff — methods, history, and uses Threshing Threshing separates edible grain from the surrounding chaff. Overview of traditional and modern techniques, historical development, byproducts and cultural importance in grain proc…

Thunbergia: tropical vines and flowering ornamentals Thunbergia Thunbergia is a genus of tropical Acanthaceae vines and herbs, prized for showy tubular flowers (clockvine, black-eyed Susan vine) and used widely in gardens; some species can natu…

Thyme (Thymus): description, uses, cultivation and varieties Thyme Thyme is a diverse genus of aromatic perennial herbs in the mint family (Lamiaceae). Widely used in cooking, medicine and landscaping, its small evergreen leaves and flowers suppor…

Thymelaeaceae — the mezereum family of flowering plants Thymelaeaceae Thymelaeaceae is a family of woody and herbaceous flowering plants found worldwide, especially diverse in Africa and Australia; many species are ornamental, fibrous, or economicall…

Tilia (linden or lime): description, characteristics, uses, and history Tilia Tilia is a genus of deciduous trees and shrubs (linden or lime) of the Northern Hemisphere, valued for shade, timber, fragrant flowers for honey and tea, and cultural significance…

Tilia nasczokinii (Nasczokin's linden) — a rare Siberian linden species Tilia nasczokinii Tilia nasczokinii is a little-known, rare linden native to Siberian Scots pine forests. A deciduous shrub or tree up to 20 m, it is named for botanist Vladimir D. Nashchokin and is…

Titan arum (Amorphophallus titanum) Titan arum A giant tropical flowering plant from Sumatra notable for the world’s largest unbranched inflorescence, a strong carrion-like odor that attracts insect pollinators, and irregular,…

Tobacco Tobacco is a prepared plant product from Nicotiana leaves used historically and today for smoking, chewing, and nicotine extraction; its cultivation, processing, health effects and…

Tonka bean (Dipteryx odorata): description, uses and regulation Tonka bean The tonka bean is the seed of Dipteryx odorata, valued for a sweet, vanilla-like aroma and used in perfumery and flavoring; it contains coumarin and is regulated in some countries.

Touch‑me‑not (plants) Touch-me-not Common name for several unrelated plants noted for touch‑sensitive or explosive seed responses, chiefly Impatiens species and Mimosa pudica; covers features, uses, and distinctions…

Tracheid — water-conducting and support cell of xylem Tracheid Tracheids are elongated, lignified cells in the xylem of vascular plants that move water and minerals and provide mechanical support; dominant in many gymnosperms and softwoods.

Translocation (botany): movement of organic compounds and ions in vascular plants Translocation (botany) Translocation is the directed transport of organic molecules, signalling compounds and some mineral ions through vascular tissue—primarily phloem—supporting growth, storage and who…

Transpiration: how plants lose and move water Transpiration Transpiration is the evaporation of water from plants, mainly via leaf stomata. It drives upward water movement, cools tissues, and affects ecosystems and agriculture. Covers mecha…

Tree: structure, function, and importance Tree A tree is a perennial woody plant with a single main stem. This article explains its parts, growth, physiology, ecological roles, uses and differences from shrubs.

Tree fern Tree ferns are large, tree‑like ferns with a trunk formed by root masses, large divided fronds, spore reproduction, an ancient fossil history, and important ecological and horticul…

Tree line (timberline): the ecological boundary of tree growth Tree line The tree line (timberline) is the ecological limit where trees can no longer establish and grow. This article explains its types, causes, ecological importance, and how it is affec…

Trichome: Plant Surface Hairs — Types, Structure, and Biological Roles Trichome Trichomes are hairlike outgrowths from plant epidermis. This article explains their forms, functions, evolutionary roles, economic importance, and notable examples.

Trifolium pratense (Red Clover): biology, habitat and uses Trifolium pratense Red clover (Trifolium pratense) is a short-lived perennial legume native to Europe, North Africa and temperate Asia. Valued as forage, a cover crop and a nectar source; notable for…

Triodia — Australian hummock grasses commonly called spinifex Triodia Triodia is a genus of perennial, hummock-forming grasses endemic to arid Australia. Known as spinifex, these spiky plants have cultural, ecological and practical importance for Ind…

Triphyophyllum — the three-leaved carnivorous liana (Triphyophyllum peltatum) Triphyophyllum Triphyophyllum is a monotypic genus of carnivorous liana from West African rainforests, known for a rare three-stage lifecycle with distinct leaf forms and highly restricted cultiv…

Tropaeolum — the nasturtiums: a genus of ornamental and edible flowering plants Tropaeolum Tropaeolum is a genus of about 80 species of annual and perennial herbaceous flowering plants native to Central and South America, known for showy spurred flowers, peltate leaves a…

Trunk (botany): structure, function, and importance of a tree's main stem Trunk (botany) The trunk (bole) is a tree's primary woody stem connecting roots and branches. This article explains its layers, growth processes, ecological roles, uses in timber, and variation a…