Pemphis acidula, commonly known as the grey mangrove or smooth-barked mangrove, is a species of mangrove shrub or small tree. It belongs to the family Lythraceae and is found in coastal regions of the Indo-Pacific, including countries such as India, Sri Lanka, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, and Australia.

Pemphis acidula is characterized by its compact, twisted growth habit and smooth, greyish bark. It has small, opposite leaves that are thick and leathery. The shrub produces small, inconspicuous flowers and fruit.

This mangrove species is well adapted to survive in harsh coastal environments with high salinity and fluctuating water levels. It typically grows on sandy or rocky shores, often on exposed headlands or fringing coral reefs.

Pemphis acidula plays a role in stabilizing coastlines and protecting against erosion, particularly in areas prone to wave action. It also provides habitat for various organisms, such as birds, insects, and crabs.

In addition to its ecological significance, Pemphis acidula has cultural and medicinal uses in some regions. Its wood is sometimes used for carvings or as a source of fuel, while its extracts have been utilized in traditional medicine for their potential antimicrobial and anti-inflammatory properties.