the plant world of the littoral zone. In seas the littoral flora consists principally of green, brown, red, and blue-green algae, which are attached to the bottom. The specific composition of the flora changes substantially from the upper level of the littoral to the lower. The properties of the bottom have greatly determined the distribution of the flora. For example, the littoral flora on stony bottoms is richer than that on soft ground.
Littoral flora develops most luxuriantly in the temperate zone. Green algae grows primarily in the upper level of the littoral, and brown and red algae in the middle and lower levels. In northern latitudes the littoral flora is poorly developed. In the tropics, on sections of the coast that are subject to direct sunlight, the littoral flora is represented by mangrove trees and, more rarely, by herbs and algae.
The littoral flora plays a large role on seacoasts as the principal source of accumulated organic matter. It also is important as a refuge and often as food for animals that inhabit the littoral. The littoral flora of inland bodies of water occupies an extensive zone up to the boundary of deep-water distribution of vegetation and consists principally of flowering plants.