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A Silver Fir shoot showing three successive years of retained leaves

In botany, an evergreen plant is a plant having leaves all year round. This contrasts with deciduous plants, which completely lose their foliage for part of the year. Evergreen is the name of several places in the United States of America: Evergreen, Alabama Evergreen, Colorado Evergreen Park, Illinois Evergreen, Louisiana Evergreen, Wisconsin Evergreen Township, Michigan The term evergreen also has botanical meanings. ... Image File history File links This is a lossless scalable vector image. ... Download high resolution version (1624x1122, 300 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1624x1122, 300 KB) Wikipedia does not have an article with this exact name. ... Binomial name Abies alba Mill. ... Pinguicula grandiflora commonly known as a Butterwort Example of a cross section of a stem [1] Botany is the scientific study of plant life. ... Look up foliage in Wiktionary, the free dictionary. ... For other uses, see Deciduous (disambiguation). ... “Foliage” redirects here. ...

Leaf persistence in evergreen plants may vary from a few months (with new leaves constantly being grown and old ones shed), to several decades (over thirty years in Great Basin Bristlecone Pine Pinus longaeva ^[1]). Binomial name Pinus longaeva D.K.Bailey The Great Basin Bristlecone Pine (Pinus longaeva) is one of the bristlecone pines, a group of three species of pine found in the higher mountains of the southwest United States. ...

A Southern live oak in winter

One additional special case exists in Welwitschia, an African gymnosperm plant which produces only two leaves, which grow continuously throughout the plant's life but gradually wear away at the apex, giving about 20–40 years' persistence of leaf tissue. Live Oak tree in a pasture Image taken by me, released under GFDL Pollinator 01:58, 17 Feb 2004 (UTC) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Live Oak tree in a pasture Image taken by me, released under GFDL Pollinator 01:58, 17 Feb 2004 (UTC) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Binomial name Quercus virginiana Mill. ... Binomial name Hook. ... World map showing location of Africa A satellite composite image of Africa Africa is the worlds second_largest continent in both area and population, after Asia. ... Divisions Pinophyta (or Coniferophyta) - Conifers Ginkgophyta - Ginkgo Cycadophyta - Cycads Gnetophyta - Gnetum, Ephedra, Welwitschia Gymnosperm (Gymnospermae) are a group of spermatophyte seed-bearing plants with ovules on the edge or blade of an open sporophyll, which are usually arranged in cone-like structures. ... Leaves are an Icelandic five-piece alternative rock band who came to prominence in 2002 with their debut album, Breathe, drawing comparisons to groups such as Coldplay and Doves. ... Look up foliage in Wiktionary, the free dictionary. ...

There are many different types of evergreens, both trees and shrubs, including most species of: conifers (e.g. white/scots/jack pine, red cedar, blue spruce), holly, hemlock, 'ancient' gymnosperms like cycads, rainforest trees and Eucalypts. Orders & Families Cordaitales † Pinales   Pinaceae - Pine family   Araucariaceae - Araucaria family   Podocarpaceae - Yellow-wood family   Sciadopityaceae - Umbrella-pine family   Cupressaceae - Cypress family   Cephalotaxaceae - Plum-yew family   Taxaceae - Yew family Vojnovskyales † Voltziales † “Conifer” redirects here. ... There are three main subgenera of Pinus, the subgenus Strobus (White pines or soft pines), the subgenus Ducampopinus (Pinyon, Bristlecone and Lacebark pines), and the subgenus Pinus (Typical pines, or yellow or hard pines). ... Binomial name L. Distribution The Scots Pine (Pinus sylvestris L.; family Pinaceae) is a species of pine native to Europe and Asia, ranging from Great Britain and Spain east to eastern Siberia, south to the Caucasus Mountains, and as far north as Lapland. ... Binomial name Pinus banksiana Lamb. ... Binomial name Thuja plicata Donn ex D.Don Thuja plicata (Western Redcedar) is a species of thuja, an evergreen coniferous tree in the cypress family Cupressaceae, native to the northwestern United States and southwestern Canada, from southern Alaska and British Columbia south to northwest California and inland to western Montana. ... Binomial name Picea pungens Engelm. ... This article is about the plant. ... Species Eastern Hemlock Carolina Hemlock Taiwan Hemlock Northern Japanese Hemlock Himalayan Hemlock Forrests Hemlock Western Hemlock Mountain Hemlock Southern Japanese Hemlock Tsuga is a genus of conifers in the family Pinaceae. ... Families Cycadaceae cycas family Stangeriaceae stangeria family Zamiaceae zamia family Leaves and male cone of Cycas revoluta Cycads are an ancient group of seed plants characterized by a large crown of compound leaves and a stout trunk. ... For the novel, see Rainforest (novel). ... Eucalypts are tree species belonging to three closely related genera, Angophora, Corymbia and Eucalyptus. ...

Reasons for being evergreen or deciduous

Deciduous trees shed their leaves usually as an adaptation to a cold season or a dry season. Most tropical rainforest plants are evergreens, replacing their leaves gradually throughout the year as the leaves age and fall, whereas species growing in seasonally arid climates may be either evergreen or deciduous. Most warm temperate climate plants are also evergreen. In cool temperate climates, fewer plants are evergreen, with a predominance of conifers, as few evergreen broadleaf plants can tolerate severe cold below about -30 °C. Tropical and subtropical moist broadleaf forests of the world Tropical rainforests are rainforests generally found near the equator. ... In geography, temperate latitudes of the globe lie between the tropics and the polar circles. ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants or angiosperms are the most widespread group of land plants. ... Psychrophiles are extremophilic organisms that are capable of growth and reproduction in cold temperatures. ...

In areas where there is a reason for being deciduous (e.g. a cold season or dry season), being evergreen is usually an adaptation to low nutrient levels. Deciduous trees lose nutrients whenever they lose their leaves, and they must replenish these nutrients from the soil to build new leaves. When few nutrients are available, evergreen plants have an advantage. In warmer areas, species such as some pines and cypresses grow on poor soils and disturbed ground. In Rhododendron, a genus with many broadleaf evergreens, several species grow in mature forests but are usually found on highly acidic soil where the nutrients are less available to plants. In taiga or boreal forests, it is too cold for the organic matter in the soil to decay rapidly, so the nutrients in the soil are less easily available to plants, thus favouring evergreens. Subgenera Subgenus Strobus Subgenus Ducampopinus Subgenus Pinus See Pinus classification for complete taxonomy to species level. ... Genera Actinostrobus Athrotaxis Austrocedrus Callitris - Cypress-pine Callitropsis - Cypress * (Cupressus) Calocedrus - Incense-cedar Chamaecyparis - Cypress Cryptomeria - Sugi Cunninghamia - Cunninghamia Cupressus - Cypress Diselma - Diselma Fitzroya - Alerce Fokienia - Fujian Cypress Glyptostrobus - Chinese Swamp Cypress Juniperus - Juniper Libocedrus Metasequoia - Dawn Redwood Microbiota - Microbiota Neocallitropsis Papuacedrus * (Libocedrus) Pilgerodendron * (Libocedrus) Platycladus - Chinese Arborvitae Sequoia - Coast... Subgenera Azaleastrum Candidastrum Hymenanthes Mumeazalea Pentanthera (Azaleas) Rhododendron Therorhodion Tsutsusi (Azaleas) Vireya Source: RBG, Edinburgh Rhododendron (from the Greek: rhodos, rose, and dendron, tree) is a genus of flowering plants in the family Ericaceae. ... For other uses, see Taiga (disambiguation). ... Boreal may refer to these: Northern from the eponymous Boreas, god of the North Wind in Greek mythology. ...

In temperate climates, evergreens can reinforce their own survival; evergreen leaf and needle litter has a higher carbon-nitrogen ratio than deciduous leaf litter, contributing to a higher soil acidity and lower soil nitrogen content. These conditions favour the growth of more evergreens and make it more difficult for deciduous plants to persist. In addition, the shelter provided by existing evergreen plants can make it easier for other evergreen plants to survive cold and/or drought.^[2][3][4]

Idiomatic use

Owing to the botanical meaning, the idiomatic term "evergreen" refers to something that perpetually renews itself, or otherwise remains steady and constant (doesn't suddenly halt or "die off", as leaves on a deciduous tree.) An evergreen market, for example, is one where there is a constant, renewed demand for an item or items, as opposed to a market which is expected to eventually saturate.

References

Oecologia is an international peer-reviewed English language journal that publishes original research into topics related to ecology. ...

See also

• Deciduous
• Semi-deciduous