Plants

Watercress (Nasturtium officinale): description, cultivation and uses Watercress Watercress is a fast-growing, peppery aquatic leafy green (Brassicaceae). This article summarizes its botany, cultivation methods, culinary uses, nutrition, safety considerations a…

Waterford Nuclear Generating Station (Waterford Steam Electric Station, Unit 3) Waterford Nuclear Generating Station Single-unit nuclear power plant in St. Charles Parish, Louisiana. Waterford 3 sits on a large Mississippi River site, is operated by Entergy, and supplies baseload low-carbon elect…

Watermelon (Citrullus lanatus): description, varieties, uses and cultivation Watermelon Comprehensive overview of watermelon: botany and origins, common varieties and colors, culinary uses, cultivation and harvesting, nutritional notes and cultural significance.

Wattieza: the earliest known tree of the Middle Devonian Wattieza Wattieza is an extinct genus of tree-like plants from the mid-Devonian (~385 Ma). Fossils from New York show frond-crowned cladoxylopsids about 8 m tall that formed some of Earth's…

Weed (unwanted plant) Weed A weed is a plant considered undesirable where it grows. This article explains what makes a plant a weed, common traits, ecological and agricultural impacts, management methods, an…

Welwitschia mirabilis — the desert 'living fossil' Welwitschia Welwitschia mirabilis, a unique gymnosperm of the Namib Desert, has a compact stem and two persistent leaves. This slow‑growing plant is notable for longevity, unusual morphology,…

Wheat: biology, history, uses and health considerations Wheat Wheat (Triticum) is a globally cultivated cereal grass whose grain is milled into flour and used for breads, pasta and many foods; it shaped early civilizations and remains a major…

White currant (cultivar of the red currant) White currant White currant is a pale-fruited cultivar of the red currant (Ribes), a small European shrub grown for fresh eating, preserves and ornament; similar cultivation and uses to other cu…

White mustard (Sinapis alba) White mustard White mustard (Sinapis alba) is an annual Brassicaceae plant grown for its pale seeds, edible greens and oil; used as a condiment, cover crop and biofumigant with a long cultivatio…

White sapote (Casimiroa edulis) — subtropical fruit tree White sapote White sapote (Casimiroa edulis) is a subtropical tree native to Mexico and Central America, grown for its sweet, creamy fruit pulp. It is cultivated in several warm regions and use…

Wild grape (Vitis): description, habitat, ecology and uses Wild grape Wild grapes are native, uncultivated Vitis species with climbing woody vines, lobed leaves, and clustered berries important to wildlife and people. Found along streams, roadsides a…

Wildflower Wildflowers are flowering plants that grow and reproduce without deliberate human planting; they play key ecological roles, include native and introduced species, and face conserva…

Williams pear (Bartlett pear) Williams pear A widely grown European pear cultivar, known as Williams' Bon Chrétien in Europe and Bartlett in North America; valued for its sweet, aromatic flesh and use fresh, canned, or cooke…

Willow (Salix): biology, uses, ecology, and notable species Willow Willows (genus Salix) are deciduous trees and shrubs of wet habitats in the Northern Hemisphere, noted for flexible wood, early catkins, medicinal compounds, and roles in erosion c…

Wisteria: ornamental climbing shrub with fragrant pendulous flowers Wisteria Wisteria is a woody climbing plant prized for long clusters of fragrant blue, lilac or white blossoms. This overview explains appearance, species, cultivation, uses and safety cons…

Wollemia (Wollemi pine) Wollemia Wollemia is a rare genus of conifer in the family Araucariaceae, known from a small wild population discovered in 1994 and from a fossil record extending back about 200 million yea…

Wood: Composition, Types, Uses and Sustainability Wood Wood is the structural tissue of trees, composed mainly of cellulose and lignin. This article summarizes its structure, varieties, uses, processing, history, and environmental impo…

Sweet woodruff (Galium odoratum): description, uses and cultivation Woodruff Overview of sweet woodruff (Galium odoratum): appearance, habitat, traditional uses in gardens, herbal and culinary roles, cultivation tips, safety notes and distinguishing feature…

Xeranthemum — Mediterranean everlasting flowers Xeranthemum Xeranthemum is a small genus of Mediterranean flowering plants in the daisy family, valued for silvery, papery bracts and long-lasting dried blooms used in gardens and floral arran…

Xerochrysum — Australian everlastingflowers genus Xerochrysum Xerochrysum is a small genus of Australian flowering plants known as everlastingflowers. This article covers its features, taxonomy, species, cultivation and notable botanical rese…

Xerochrysum bicolor — a Tasmanian coastal everlasting daisy Xerochrysum bicolor Xerochrysum bicolor is a Tasmanian flowering plant in the family Asteraceae, known for its compact habit and papery flower bracts. It grows mainly in coastal areas and is valued fo…

Xerochrysum bracteatum — golden everlasting (strawflower) Xerochrysum bracteatum Comprehensive overview of Xerochrysum bracteatum (golden everlasting, strawflower): description, native range, ecology, cultivation, propagation, uses as cut and dried flower, pest…

Xerophyte: plants adapted to dry environments Xerophyte Xerophytes are plants adapted to environments with limited water. This article explains their defining traits, common adaptations, typical habitats and examples, uses, and how they…

Yam (Dioscorea): a starchy tuber and its uses Yam Yams are starchy tubers from the genus Dioscorea, cultivated in tropical regions and used across cuisines. Distinct from sweet potatoes, they vary in size, color and cultural impor…

Yerba mate (Ilex paraguariensis): plant, uses, and cultural role Yerba mate Yerba mate (Ilex paraguariensis) is a South American holly used to prepare mate, a stimulant infusion. The article covers the plant, cultivation, cultural use, preparation, and dis…

Yew (Taxus): characteristics, uses, and cultural significance Yew Yews are coniferous trees and shrubs in the genus Taxus (family Taxaceae), known for flat needles, red arils, toxic seeds, long life, timber uses and the cancer drug paclitaxel.

Yucca — drought‑tolerant flowering plants of the Americas Yucca Yucca is a genus of perennial shrubs and trees native to the Americas, known for sword‑shaped leaves, tall flower clusters, and a specialized pollination mutualism with yucca moths…

Yucca brevifolia (Joshua tree): description, ecology, and conservation Yucca brevifolia Yucca brevifolia, known as the Joshua tree, is a tree-like yucca of the Mojave Desert. This article summarizes its appearance, taxonomy, pollination, growth, cultural uses, and con…

Yuzu: an East Asian citrus fruit and its uses Yuzu Yuzu (Citrus junos) is a fragrant East Asian citrus used in cooking, condiments, and fragrances. It is valued for its aromatic rind and tart juice and has distinct culinary and cul…

Zedoary (Curcuma zedoaria) — white turmeric and aromatic rhizome Zedoary Zedoary (Curcuma zedoaria) is a perennial in the ginger family native to South and Southeast Asia. Its pale, bitter rhizome is used as a spice, in traditional medicine, and grown i…

Zenobia (plant): the honeycup shrub of southeastern North American bogs Zenobia (plant) Zenobia is a monotypic genus in the heath family (Ericaceae). Its sole species, Zenobia pulverulenta or honeycup, is a small evergreen shrub native to acidic bogs of the southeaste…

Zieria adenophora (Araluen Zieria) Zieria adenophora A small, locally endemic shrub known only from a slope above Araluen Creek, New South Wales. Rediscovered in the 1980s, it is notable for extreme rarity and focused conservation at…

Zingiberaceae (Ginger family): characteristics, uses, and distribution Zingiberaceae Zingiberaceae, the ginger family of aromatic perennial herbs with rhizomes, comprises about 50+ genera and 1,300+ species. Native to tropical Africa, Asia and the Americas; include…

Zingiberales: the tropical order that includes gingers and bananas Zingiberales Zingiberales is an order of monocot flowering plants including gingers, bananas, arrowroots and many ornamentals; primarily tropical, economically and ecologically significant.

Ziziphus (jujube): a genus of shrubs and trees producing edible fruit Ziziphus Ziziphus is a genus of about 40–50 shrubs and small trees in the buckthorn family (Rhamnaceae), known for edible jujube fruits, traditional medicinal uses and wide cultivation in w…

Ziziphus mauritiana (Indian jujube) Ziziphus mauritiana Ziziphus mauritiana, commonly called Indian jujube or ber, is a hardy fruit tree of the Rhamnaceae family grown across South and Southeast Asia for its edible drupes, adaptability,…

Zygnematophyceae: freshwater green algae including desmids and filamentous forms Zygnematophyceae Zygnematophyceae are a class of freshwater green algae (including desmids and filamentous taxa). They reproduce by conjugation, lack flagellate stages, and are closely related to l…