Avicennia Marina,commonly known as grey mangrove or white mangrove, is also called a pionner in muddy soil, is a species of mangrove tree classified in the plant family Acanthaceae(formerly in the verbenaceae or Avicenniaceae).As with other mangroves, it occurs in the intertidal zones of estuarine areas.Grey mangroves grow as a shrub or tee to a height of three to ten meters, or up to 14 meters in tropical regions.