Evergreen
An evergreen plant retains foliage throughout the year, replacing leaves or needles gradually rather than shedding them all in one season.
Leaf: A plant organ specialized for photosynthesis, gas exchange, and water regulation. Evergreen foliage consists of leaves that remain functional across multiple seasons.
Photosynthesis: The process by which plants and other organisms convert light energy into chemical energy. Evergreen leaves can photosynthesize during favorable periods throughout the year.
Conifer: A cone-bearing gymnosperm, including pines, firs, spruces, and their relatives. Many familiar evergreen trees belong to this group, though some conifers are deciduous.
Carbon cycle: The movement of carbon among organisms, the atmosphere, oceans, and Earth's crust. Year-round foliage influences when forests take up and release carbon.
Deciduous tree: A tree that sheds its leaves seasonally, usually in response to cold or drought. Deciduous trees avoid maintaining foliage through unfavorable seasons.
Needle: A slender, often wax-coated leaf found in many conifers. Needles are a familiar evergreen leaf form that limits water loss.
Transpiration: The loss of water vapor from plants, mainly through leaf pores. Persistent foliage must limit water loss when soil is frozen or dry.
Broadleaf evergreen: A plant with broad leaves that retains foliage through the year. This group shows that evergreen foliage is not limited to needle-shaped leaves.
Canopy: The upper layer of vegetation formed by the crowns of trees and other plants. Evergreen crowns maintain cover when deciduous canopies are bare.
Semi-deciduous plant: A plant that loses some or most foliage seasonally but does not become fully leafless. Its intermediate leaf-retention pattern differs from the evergreen condition.