Plants that live in the intertidal zone are those that live in sandy shores and beaches. Because of their location within or partially within sea water, plants that live in intertidal zones provide a necessary function to both the terrestrial and marine creatures who depend on the plants for sustenance and protection, according to the Andrews University Department of Biology.
Red mangrove (Rhizophora mangle) is a plant that lives in the intertidal zone. One of the four mangrove tree species, the red mangrove offers protection and stabilization to coastal areas by acting as feeding, breeding and nursery locations for animals highly dependent on mangroves such as fish and birds. These intertidal plants also produce about 3 1/2 tons of fallen leaves annually, which are a beneficial addition to the immediate food chain. The red mangrove is a tree with tall arching roots that displays green elliptical-shaped leaves and pale yellow spring flowers. Red mangroves reach 20 to 80 feet in height depending on location, according to the University of Florida IFAS Extension.
Eelgrass (Zostera marina L.) is a grass plant that lives in the intertidal zone. Though often thought of as a seaweed or an algae, eelgrass is a plant that grows beneath the water complete with leaves, inconspicuous flowers and roots, according to the Rhode Island Sea Grant at the University of Rhode Island. Eelgrass can be found in shallow waters protected by waves; such areas include bays and estuaries. Rooted in sediment with a requirement for sunlight, eelgrass is usually found no deeper in water than approximately 6 feet. Eelgrass provides nursery areas for fish, food for a variety of organisms, and structured areas to dampen waves resulting in protection from storm damage. Like terrestrial grass, eelgrass displays long blades as well as seeds for harvest.
Sea grape (Coccoloba uvifera) is one of the plants that live in the intertidal zone. The sea grape tree, according to the University of Florida IFAS Extension, is generally a multistemmed, vase-shaped tree that displays inconspicuous flowers and round, leathery, evergreen leaves with red veins; leaves turn red during the winter season. Sea grape trees also produce clusters of green grapes on female trees; grapes ripen to a purple color in late summer. Sea grape trees attract high amounts of wildlife including birds who feed on their fruit. This intertidal plant grows to a height of 25 to 30 feet.
Sea lettuce (Ulva lactuca) lives in the intertidal zone. According to the University of Rhode Island Environmental Data Center, sea lettuce looks like green seaweed in sheet-like layers of round or oval, perforated leaves; the plant appears white or black when dry. Sea lettuce often provides protective homes to small invertebrates like amphipods. Thriving in waters as deep as 75 feet and as shallow as areas of marshes and tide pools, sea lettuce grows from 6 inches to 2 feet in height.