%IMAGEGALLERY{ "%BASEWEB%.%BASETOPIC%" exclude="arrow|igp_.*" sort="name" warn="0"}%

Sonneratia alba

Sonneratia alba flower2.jpg
Sonneratia alba leaves and flowers, Singapore Photo: John Yong

Common Names

White-flowered Apple Mangrove [1], Pornupan Mangrove.

Family

Lythraceae

Sonneratia alba fruit.jpg
Sonneratia alba fruit, Singapore Photo: John Yong

Name Reference

Sonneratia alba Sm.

Origin of 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.

‘Alba’ means white (in Latin), and refers to the distinctive white stamens and petals of this species ([1]).

Summary

Sonneratia alba is another widely distributed mangrove species.

Species Feature - Showy and numerous white stamens with sometimes diminutive to absent white petals ([1]).

Description

Sonneratia alba is a spreading to columnar tree growing to 8 m high. It has cone-shaped pneumatophores to 45 cm high.

Leaves are simple, opposite, obovate-ovate (egg-shaped to inversely egg-shaped), 5-12 cm long and 2.5-9 cm wide with a 0.6-1.5 cm petiole and rounded apex.

The inflorescence is a cluster of usually 1-3 (but up to 5) flowers. The flowers have many large, white stamens.

The fruit is a swollen green berry to 4 cm wide and 3 cm long with persisting cup-like calyx tube ([2]; [3]).

Botanical Description

GROWTH FORM

Tree to 20 m, broadly spreading to columnar, much branched, evergreen; bark smooth or lightly fissured flaky, dark grey to pale fleshy green; stem base simple; roots pneumatophores cone-shaped, to 30 cm L, tip bluntly pointed, branched or twisted occasionally, base stout.

FOLIAGE

Leaves opposite, simple, leathery, glabrous, obovate-ovate to broadly elliptic, pale green, dull upper, satiny below, 5-12 cm L, 2.5-9 cm W, margin entire, apex obtuse with small thickened mucro recurved under; petiole 0.6-1.5 cm L, pale green to tinged red, terete; stipules absent.

REPRODUCTIVE PARTS

Inflorescence terminal or axillary, 1-3(-5)-flowered dichasia; flowers closed bud ellipsoidal, constricted medially, green, glossy, smooth, slightly angular, 2-3.3 cm L, 1.2-2.2 cm W, apex acute to obtuse; calyx lobes 6-7(-8), valvate, ovate-oblong, 1.3-2 cm L, 0.5-1 cm W, apex acute, inner often reddish; petals 0-6-7(-8), white, occasionally tinged green or red at base, linear or spathulate to stamen-like, membranous if linear, 1.3-3 cm L, 1-2 mm W, sometimes absent; stamens numerous along corolla rim, white, 1.5-4.5 cm L; ovary 12-20 locular; style terete, green, coiled in bud, extended at anthesis to 4.3 cm L, stigma fungiform to 3 mm W; fruit berry erect-globose, to 2.7 cm L, 2.2-4.6 cm W, persistent withered style; pericarp green, glabrous, dull; calyx persistent, tube broadly cupulate, base rounded, green, shiny, 2.5-4.1 cm W, lobes 6-7(-8) spreading pointed, 1.7-2.6 cm L; seeds numerous within fleshy pulp of placenta.

DISPERSAL PROPAGULE

Seeds irregular, sickle-shaped, falcate,to 12 mm L, buoyant; germination epigeal.

Distribution

Sonneratia alba is the most widespread of all Sonneratia species, distributed from East Africa to India and southern China, through Asia and Indonesia to the western islands of the Pacific Ocean including New Caledonia, Solomon Islands and northern Australia. In Australia, the species is found along the northern coast from Cape Bossut, Western Australia (18° 43’ S, 121° 38’ E) in the west, across the Northern Territory, to Port Clinton, Queensland (22° 35’ S, 150° 45’ E) on the east coast ([1]).

Localities (not complete):

Habitat

The trees are found mostly at lower tidal contours within frontal stands of downstream lower estuarine reaches and offshore island enclaves in regions of high to moderate rainfall where tidal ranges exceed one metre. Grows in a range of sediment types from sand, gravel or soft river muds.

Low intertidal, downstream estuarine position ([1]).

Biology

In Australia, flowering is common in October and November, and fruiting occurs mainly around February (ranging from January to March).

The species is commonly associated with Rhizophora stylosa, Aegiceras corniculatum and Avicennia marina ([1]).

Biological Interactions  
Group Taxon
  18 taxa  
Vascular Plants Aegialitis_annulata
Vascular Plants Aegiceras corniculatum
Vascular Plants Avicennia marina
Vascular Plants Bruguiera gymnorhiza
Vascular Plants Bruguiera parviflora
Vascular Plants Camptostemon schultzii
Vascular Plants Ceriops tagal
Vascular Plants Cynometra iripa
Vascular Plants Excoecaria agallocha
Vascular Plants Heritiera littoralis
Vascular Plants Lumnitzera littorea
Vascular Plants Nypa fruticans
Vascular Plants Rhizophora apiculata
Vascular Plants Rhizophora mucronata
Vascular Plants Rhizophora stylosa
Vascular Plants Xylocarpus granatum
Vascular Plants Bruguiera sexangula
Vascular Plants Hibiscus tiliaceus

Sonneratia alba roots.jpg
The conical breathing roots (pneumatophores) of Sonneratia alba are more apparent when there is some surface erosion, Singapore. Photo: John Yong

Similar Species

Sonneratia alba is distinguished from other Sonneratia by: its white stamens rarely tinged pink at the base; petals that are variably present and often intermediate in shape with stamens; rounded dull leaves being pale grey-green with rounded apices; sickle-shaped seeds; and, a cup-shaped calyx beneath the mature fruit, being an erect-sided globose berry with a dull surface ([1]).

Notes

The occurrence of intermediate or apetalous forms appear related to marginal habitats and certain ecological factors. For instance, in colder latitudes, towards southern distributional limits, apetalous and semi-petalous forms appear more common. In more equatorial areas, by contrast, fully-petalled forms are common in riverine estuaries while less-petalled forms occur more frequently offshore on smaller rocky islands and coral cays ([1]).

Mangrove Watch: http://www.mangrovewatch.org.au/index.php?option=com_content&view=category&layout=blog&id=41&Itemid=300196

FloraBase: http://florabase.calm.wa.gov.au/browse/profile/5288

-- NormDuke and EmmaClifton - 2012-01-05 - 11:08

Sonneratia alba bud flower.jpg
Sonneratia alba buds and flowers, Singapore Photo: John Yong

Sonneratia alba habit.jpg
Sonneratia alba can grow in excess of 20 m in the right conditions, Singapore. Photo: John Yong

Sonneratia comparision2.jpg
Sonneratia alba (right). For comparison, Sonneratia ovata (left, doesn't occur in Australia) and Sonneratia caseolaris (middle), Singapore. Photo: John Yong

References

  1. Duke, N. (2011). Mangroves of Australia. Manuscript. Vers.: 27 Sept 2011. (more)
  2. Duke, N.C. (2006). Australia's Mangroves. The authoritative guide to Australia's mangrove plants. University of Queensland, Brisbane. (more)
  3. Wightman, G. (2006b). Mangrove Plant Identikit from north Australia's Top End. Greening Australia NT, Darwin. (more)
  4. Bunt, J.S. (1982b). Mangrove Transect Data from Northern Queensland. Coastal Studies Series, Australian Institute of Marine Science AIMS-CS-82-1. Australian Institute of Marine Science. 41 p. Available online: http://data.aims.gov.au/extpubs/attachmentDownload?docID=2326 (more)
  5. Abrantes, K. & Sheaves, M. (2009). Food web structure in a near-pristine mangrove area of the Australian wet tropics. Estuarine, Coastal and Shelf Science 82: 597-607. Available online: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WDV-4VRP291-5-1&_cdi=6776&_user=2322062&_pii=S0272771409000833&_origin=search&_coverDate=05,2F20,2F2009&_sk=999179995&view=c&wchp=dGLbVlz-zSkWA&md5=c28b26c1693d6440f7e0ea9b8727b258&ie=/sdarticle.pdf (more)
  6. Bunt, J.S. (1997). The Mangrove Floral and Vegetational Diversity of Hinchinbrook Island and the Adjacent Coast. Australian Institute of Marine Science, Townsville. Available online: http://data.aims.gov.au/extpubs/attachmentDownload?docID=3018 (more)

Biological Interactions
Relation Taxon GroupSorted ascending
PreyOf Polystigma_sonneratiae Fungi
HasEpiphyte Bostrychia_calliptera RedAlgae
HasEpiphyte Bostrychia_moritziana RedAlgae
HasEpiphyte Bostrychia_simpliciuscula RedAlgae
HasEpiphyte Caloglossa_adhaerens RedAlgae
HasEpiphyte Caloglossa_stipitata RedAlgae
HasEpiphyte Catenella_nipae RedAlgae
HasEpiphyte Gelidium_sp RedAlgae
HasEpiphyte Stictosiphonia_kelanensis RedAlgae
OccursWith Aegialitis_annulata Vascular_Plants
OccursWith Aegiceras_corniculatum Vascular_Plants
OccursWith Avicennia_integra Vascular_Plants
OccursWith Avicennia_marina Vascular_Plants
OccursWith Bruguiera_gymnorhiza Vascular_Plants
OccursWith Bruguiera_parviflora Vascular_Plants
OccursWith Bruguiera_sexangula Vascular_Plants
OccursWith Camptostemon_schultzii Vascular_Plants
OccursWith Ceriops_tagal Vascular_Plants
OccursWith Cynometra_iripa Vascular_Plants
OccursWith Excoecaria_agallocha Vascular_Plants
OccursWith Heritiera_littoralis Vascular_Plants
OccursWith Hibiscus_tiliaceus Vascular_Plants
OccursWith Lumnitzera_littorea Vascular_Plants
OccursWith Nypa_fruticans Vascular_Plants
OccursWith Rhizophora_apiculata Vascular_Plants
OccursWith Rhizophora_mucronata Vascular_Plants
OccursWith Rhizophora_stylosa Vascular_Plants
OccursWith Xylocarpus_granatum Vascular_Plants