Australian Tropical Rainforest Plants - Online edition

Ostrearia australiana Baill.

Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Leaves and Flowers. © CSIRO
Fruit dehiscing. © CSIRO
Fruit, dehiscing and seeds. © W. T. Cooper
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO

Baillon, H.E. (1873) Adansonia 10: 131. Type: Queensland, Rockingham Bay, J. Dallachy, holo: P. Fide L. S. Smith, Proc. Roy. Soc. Queensland 69: 43 (1958).

Common name

Hard Pink Alder; Alder, Hard Pink


Usually encountered as a small tree to 30 cm dbh but recorded to 40 cm dbh. Lenticels often arranged in longitudinal lines.


Stipules about 5-7 x 1-2 mm, scars thin, encircling the twigs. Lenticels usually obvious on the twigs. Leaf blades about 11-19 x 4.5-8 cm. Lateral veins forming loops well inside the blade margin.


Inflorescence about 1.7-3 cm long, very dense. Calyx hairy or stellate lepidote. Petals linear, about 10-12 mm long, coiled in the bud. Staminodes five. Apex of the ovary stellate hairy or stellate scaly.


Fruits +/- glabrous with only the very base enclosed in the remains of the hypanthium. Each fruit is a one or 2-lobed capsule with the capsules aggregated in an irregular fashion on a central axis 2-5 cm long. Seeds about 10-12 x 6 mm. Embryo about 9 mm long, cotyledons +/- orbicular, about 7-8 mm diam. The remains of the fruit are often present on the ground beneath mature trees.


Cotyledons almost orbicular, about 30-49 mm diam. At the tenth leaf stage: leaf blade elongate-elliptic, apex acute or acuminate, base cuneate, glabrous; stipules linear; a few scattered pale brown stellate scales visible on the stipules and terminal bud. Seed germination time 38 to 40 days.

Distribution and Ecology

Endemic to NEQ, occurs from Rossville to Tully. Altitudinal range from near sea level to 800 m. Grows in well developed lowland and foothill rain forest, frequently near permanent creeks.

Natural History & Notes

A rare species.

Wood specific gravity 0.75. Cause et al. (1989).

RFK Code
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