Species: Avicennia marina

Status (IUCN): Least concern. However, mangrove forests are considered highly significant ecological communities and are overall in decline in many areas due to localised threats and climate change. Grey Mangrove (Avicennia marina) is the most common and widespread mangrove species.

Characteristics

• Height:  2 – 10m high (but can be up to 25m high).
• Trunk: large, the bark is finely fissured and grey. 
• Roots: Spongy, pencil-like roots called pneumatophores, which are specialised root structures that grow vertically and spread out from the trunk, enabling the mangrove roots to breathe in the intertidal zone. The pneumatophores are covered in lenticels (air pores), which assist with atmospheric gas exchange.
• Leaf Identification:  Leathery and narrow-obovate to obovate-lanceolate (generally oval and pointed), arranged opposite one another on the stems. It can be up to 8 cm long and 5cm wide.
• Leaf Colour: Glossy green on the upper side, and pale grey and slightly hairy on the reverse side, with special glands for excreting excess salt.
• Flowers: Yellow or orange, in small dense clusters.
• Fruits and seeds: The fruits are almond sized, pale green and hairy, 2 cm long and 3 cm wide. They are compressed ovoid capsules covered by the pericarp, and each fruit holds a single seed.

Reproduction: Bisexual flowers appear in mid-late summer through early autumn. The fruits mature after two months, ripening in the summer. As a viviparous species, the seeds (propagules) partially germinate inside the fruit while still attached to the tree, allowing for quick establishment once they settle in a location with ideal conditions, either close to the parent tree in muddy/sandy soil or dispersed by tidal water movement. Seedlings can stay small and survive with just a few leaves for many years. They wait for an opening in the canopy such as from the fall of an old tree to then develop into a tree.

Habitat: Intertidal zones with soft, muddy and sandy soils (but not on pure mud) such as the seashore, wetlands, and the margins of tidal estuaries, creeks and rivers. It may grow with river, red and other mangrove species. As a pioneer species, it colonises an area and develops mud banks.