Any of certain shrubs and trees of the families Rhizophoraceae, Verbenaceae, Sonneratiaceae, and Arecaceae ( palm ) that grow in dense thickets or forests along tidal estuaries, in salt marshes, and on muddy coasts.
The term also applies to the thickets and forests of such plants. Mangroves characteristically have prop roots (exposed, supporting roots). In addition, in many species respiratory, or knee, roots project above the mud and have small openings through which air enters, passing through the soft, spongy tissue to the roots beneath the mud. Mangrove fruits put out an embryonic root before they fall from the tree; the root may fix itself in the mud before the fruit separates from the parent. Likewise, branches and trunks put out adventitious roots which, once they are secure in the mud, send up new shoots. The common mangrove ( Rhizophora mangle ) grows to about 30 ft (9 m) tall and bears short, thick, leathery leaves on short stems, and pale-yellow flowers. Its fruit is sweet and wholesome.