evergreen, any plant that retains its leaves through the year and into the following growing season. Many tropical species of broad-leaved flowering plants are evergreen, but in cold-temperate and Arctic areas the evergreens commonly are cone-bearing shrubs or trees (conifers), such as pines and firs. The leaves of evergreens usually are thicker and more leathery than those of deciduous trees (those that shed their leaves in autumn or in the tropical dry season) and often are needlelike or scalelike in cone-bearing trees. A leaf may remain on an evergreen tree for two years or longer and may fall during any season. An evergreen forest may be needle-leaved, as the coniferous forests of the Northern Hemisphere, or broad-leaved, as the temperate rain forests of the Southern Hemisphere and the broad sclerophyll forests (with thickened, hardened foliage resistant to water loss) of coastal areas of the Northern Hemisphere. Most tropical rain forests contain broad-leaved evergreens. See also coniferous forest; chaparral.

This article was most recently revised and updated by Chelsey Parrott-Sheffer.
Britannica Chatbot logo

Britannica Chatbot

Chatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.

conifer, any member of the division Pinophyta, class Pinopsida, order Pinales, made up of living and fossil gymnospermous plants that usually have needle-shaped evergreen leaves and seeds attached to the scales of a woody bracted cone. Among living gymnosperm divisions, the conifers show little similarity to the Cycadophyta and Gnetophyta but share several vegetative and reproductive traits with the Ginkgophyta. Conifers are most abundant in cool temperate and boreal regions, where they are important timber trees and ornamentals, but they are most diverse in warmer areas, including tropical mountains.

General features

Diversity of size and structure

The conifers are the most varied gymnosperms. The world’s oldest trees are the 5,000-year-old bristlecone pines (Pinus longaeva) of desert mountains in California and Nevada. The largest trees are the giant sequoias (Sequoiadendron giganteum) of the Sierra Nevada of California, reaching heights of more than 95 metres (312 feet) and weights of at least 2 million kilograms (4.4 million pounds; compared with 190,000 kilograms for the largest recorded blue whale). Wherever conifers grow, especially in temperate climates, one of these species is usually the tallest tree. In fact, the very tallest trees are the coast redwoods (Sequoia sempervirens) of coastal California, some of which are more than 110 metres (361 feet) tall.

The world’s smallest trees probably are also conifers: the natural bonsai cypresses (Cupressus goveniana) and lodgepole pines (Pinus contorta) of the pygmy forests (adjacent to the towering redwood forests) of the northern California coasts. On the sterile hardpan soils of those astounding forests, the trees may reach full maturity at under 0.2 metre (0.7 foot) in height, while individuals of the same species on richer, deeper soils can grow to more than 30 metres (98 feet). Other conifers, such as the pygmy pine (Lepidothamnus laxifolius) of New Zealand, the smallest conifer, are always shrubby and may mature as shorter plants (less than 8 centimetres [3.15 inches] in height) than the pygmy cypress, but with greater spread.

Britannica Chatbot logo

Britannica Chatbot

Chatbot answers are created from Britannica articles using AI. This is a beta feature. AI answers may contain errors. Please verify important information using Britannica articles. About Britannica AI.