Sonneratia alba

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‘Apple Mangroves’

Sonneratia fruit Sonneratia alba tree

3 species & 2 hybrids in Australia

Mature fruits have a persistent star-shaped calyx. The genus Sonneratia L.f. (1782) belongs to the Sonneratiaceae Engl. & Gilg, a small tropical family of the order Myrtales with just two genera restricted to the Indo-West Pacific region. Sonneratia consist entirely of mangrove trees, while the other genus Duabanga made up of small evergreen rainforest shrubs from Indo-Malaya. Sonneratia are notable for their large showy flowers with numerous red or white stamens and their berry-shaped fruit seated on a persistent calyx with 6-8 erect pointed lobes. Fruits enclose a firm pulp imbedded with numerous small seeds that commonly germinate on exposed mud banks.

Sonneratia grow mostly along banks of tidal rivers, creeks and within sheltered bays of offshore islands and reef cays. In estuaries, they occupy distinct upriver ranges where: sibling species, S. caseolaris and S. lanceolata, occur in upstream reaches of river-dominated estuaries; S. alba occurs in downstream stands and offshore island embayments; and S. X gulngai and S. X urama, the two Australasian hybrids occur in small intermediate stands between the respective parents. Another species just north in New Guinea, S. ovata Backer, prefers a different habit, occurring at the high tide margin.

Derivation of Genus Name

Named for the French naturalist, Pierre Sonnerat (1748-1814), remembered for his explorations of New Guinea, Moluccas and China, including the first European description of lychee fruit.


Sonneratia occur throughout the Indo-West Pacific region from East Africa to China, through Asia and Indonesia, to New Guinea, the western Pacific and northern Australia. In Australia, there are three species and two hybrids. A third hybrid, S. alba X S. gulngai, is known only as a single tree in the McIvor River, north-eastern Australia.

World Sonneratia distribution

Key to Australia's Sonneratia species

Sonneratia species key

Australian Sonneratia distributionThree Sonneratia species and two widely-occurring hybrids are recognised in Australia’s mangroves across the northern coast from Western Australia, Northern Territory and Queensland. They are distinguished by colour of petals and stamens, calyx surface, shape of the calyx on mature fruit, plus the shape of leaves and leaf apices.

Community Volunteers

A key feature of MangroveWatch is its close partnership between community volunteers and scientists from the James Cook University’s Mangrove Hub. Together they are systematically recording basic data as video and still imagery for assessments of estuarine habitat health.

Armed with expert support, training and advice, MangroveWatch volunteers in key regions are actively contributing to the monitoring of local estuaries and shorelines. An important goal in this phase of the program is to develop a network of like minded groups with the aim of producing public documents that describe important issues affecting local estuaries and mangroves, and their overall health.

Getting Involved

If you would like to find out more about us or if you like to initiate your own MangroveWatch group within your area, please contact someone at the Mangrove Hub. We will be happy to help.

  • Mangrove Hub Facilitator
  • Dr Norm Duke
  • MangroveWatch Ltd
    ABN: 44 153 297 771
  • PO Box 1250,
  • Elanora Q 4221
  • Mangrove Hub Email

Mangrove Watch Brochure

You can download our fact and information sheet (see link below) to get more information about the MangroveWatch programs.

Mangrove Watch Brochure