Avicennia

Avicennia is a genus of flowering plants in the family Acanthaceae, commonly known as mangroves. It comprises several species of woody evergreen trees and shrubs that occupy intertidal zones in tropical and subtropical coastlines around the world, including Asia, Africa, the Americas, and parts of Oceania. The two best-known species are Avicennia marina, the grey mangrove, and Avicennia germinans, the black mangrove, though other species occur in distinct regions. Species vary in size from small shrubs to trees reaching 20–25 meters in height, and they often possess pneumatophores or breathing roots in waterlogged soils to facilitate gas exchange. Leaves are generally opposite or subopposite, with a glossy surface; many species have specialized salt-secreting glands on the leaf blade to regulate salt balance.

Avicennia shows viviparous germination, with propagules developing on the parent tree and dropping into mud or water where they establish roots. The genus plays an important ecological role: mangrove forests stabilize shorelines, trap sediment, support fisheries, and sequester carbon. They tolerate high salinity and periodic inundation, but are threatened by habitat loss due to coastal development, pollution, and rising sea levels. Taxonomically, Avicennia is classified in the family Acanthaceae (formerly placed in Avicenniaceae); the name honors Avicenna (Ibn Sina), the Persian polymath.