Botanical name:

Avicennia marina

Common name(s):

Manawa, mangrove

About:

Small yellowish-green tree that often forms dense groves on coastal mudflats, particularly in the upper regions of New Zealand's North Island. The leaves are leathery in texture, tapering elegantly to a pointed tip and displaying a paler hue on their undersides. The flowers of the tree are rather inconspicuous, blending in with their surroundings. The fruit produced is large, yellowish, and has a leathery exterior, typically falling from the tree and subsequently floating on the incoming tide.

Natural habitat:

Strictly coastal. usually inhabiting tidal river banks and river flats, estuaries and shallow harbour entrances. An important vegetation type and key ecosystem of many northern North Island harbours and estuaries. Generally favoring mud or silt-rich substrates but also found on sand, especially along channels. Avicennia flourishes where silt and mud has accumulated and in some harbours, especially those abutting cities it has become a problem species. The increase of Avicennia is however a symptom of a more serious issue, that is the impact of increased sedimentation rates within harbours whose catchments have been seriously degraded and/or deforested. It should also be noted that the argument that Avicennia ecosystems in New Zealand are as productive as tropical mangal systems has yet to be demonstrated conclusively. In many places Avicennia has replaced the demonstrably more important and productive Zostera grass beds with potentially serious long-term consequences for our near shore fisheries.

Growing environment:

Sun, Salt & Coastal tolerant.

Endemic distribution:

New Zealand: North Island from Parengarenga Harbour south to Kawhia and Ohiwa Harbours. Australia (Queensland, New South Wales, Victoria), Lord Howe Island. In New Zealand Avicennia has been deliberately and extremely irresponsibly naturalised at Tolaga Bay, Mohakatino River, and formerly in the Hutt River and Parapara Inlet (Golden Bay) - where it has since been eradicated.

Height: 10m

Flowering:

February – April with a orange or yellow coloured flower/s

Fruiting:

December - January

Uses:

Bird food / Attractant, Bee food, Hedging, Riparian plantings, Forests, Pioneer Plantings & Shelter belts, timber

How to grow:

Easily grown from ripe fruit which is usually partially germinated when it falls from the tree. Can be grown in normally potting mix but does best immersed in soil within brackish water. Avicennia can be easily translocated and as such has been moved in New Zealand by people outside its natural range. Although it is frost tender, once established plants are capable of tolerating much heavy frosts than has been assumed.