Heritiera fomes is a species of mangrove tree in the family Malvaceae. Its common names include sunder, sundri, jekanazo and pinlekanazo. It is the dominant mangrove tree species of the Sundarbans of Bangladesh and India, and comprises about 70% of the trees in the area. H. fomes is a major timber-producing tree. It is threatened by over-harvesting, water diversions in the Ganges Basin, fluctuations in salinity due to upstream and coastal development and top dying disease. The International Union for Conservation of Nature has assessed it as being "endangered".