Australian Tropical Rainforest Plants - Online edition

Bombax ceiba var. leiocarpum A.Robyns

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Flowers. © B. Gray
Flowers. © CSIRO
Fruit, side view, dehiscing and seeds. © W. T. Cooper
Scale bar 10mm. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO

Robyns, A.G.M.W.A. (1963) Bulletin Jardin Botanique Bruxelles 33: 97. Type: Northern Territory, Specht 1175. Holo:L, Iso; K,US.

Common name

Northern Cottonwood; Kapok; Kapok Tree; Red Kapok; Red Silk-cotton Tree; Red Flowered Kapok; Bombax; Semul; Silk Cotton Tree


Deciduous; leafless for a period between July and November. Pink fibrous and white granular stripes in the outer blaze. Short stout conical prickles present on the trunks of some trees.


Leaves palmately compound. Terminal buds and young shoots clothed in pale brown stellate and silky hairs. Leaf bearing twigs stout, about 10 mm diameter and rather pithy. Midrib usually raised on the upper surface of the leaflet blade. Leaflet blades about 12-18 x 3.5-5.5 cm.


Flowers usually produced when the tree is leafless. Flowers large. Corolla about 6-8 cm long, densely stellate hairy outside, but almost glabrous inside. Stamens fused to form a central column and also into groups +/- alternating with petals.


Capsules about 10 cm long, densely packed with large quantities of cream fibrous material which resembles cotton wool and surrounds the seed, but is not really attached to the seed.


Cotyledons cordate, apex acuminate. Root thickened, carrot-like (Daucus carota). At the tenth leaf stage: leaves palmate, leaflets about five, elliptic, apex acuminate, base attenuate; stipules triangular, papery. Seed germination time 8 to 10 days.

Distribution and Ecology

Widespread in WA, NT, CYP and NEQ. Altitudinal range from sea level to about 300 m. Usually grows in monsoon forest and drier rain forest. Also occurs in Malesia, Asia and the Indian sub-continent.

Natural History & Notes

The large fruit of this species yield an inferior grade of kapok that is sometimes used in India. Cooper & Cooper (1994).

Food plant for the larval stages of the Common Aeroplane Butterfly. Common & Waterhouse (1981).

Often planted in large gardens and parks for the large red flowers.

Flowers are produced in the dry season when the tree is completely leafless and when most other forms of vegetation in the community are looking rather drab and forlorn.

Bombax ceiba L., Species Plantarum 2: 511(1753), Type: Habitat in Indie utraque.
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