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A small, pantropical family especially diverse in South America, three members for the family Bombacaceae occur in northern Australia. Camptostemon is a mangrove, while Bombax and Adansonia (the boab) occur in dry rain forests or open savannahs.

Characteristic features of the family Bombacaceae in Australia include:

  • large-leaved trees or shrubs, often dry-season deciduous, some with swollen trunks, others with stout conical prickles on trunk and branches
  • leaves simple or digitately compound
  • flowers, showy, open, with 5 red or white petals, and numerous stamens with filaments forming a tube
  • fruits are capsules, often large, with numerous seeds embedded in pithy flesh or with cottony hairs


Evergreen or deciduous trees or shrubs. Stems unarmed or with prickles or spines arising from the stem surface. Internal secretions of resin. Plants with stellate, non-glandular, unicellular hairs or peltate scales. Leaves (seasonally absent) alternate and spiral, petiolate. Stipules present, distinct and free from the petiole, scale-like, or membranous, or green and leafy, often falling off early and thus apparently absent. Lamina simple or once compound, palmate, symmetric; lamina/leaflets lanceolate, ovate, elliptic, oblanceolate or obovate; base cuneate, attenuate or rounded; margins entire, ±flat; venation pinnate, with the midrib conspicuous, and the tertiary venation not reticulate; surfaces not punctate; herbaceous or leathery. Plants with all the flowers bisexual. Inflorescences axillary or terminal, consisting of cymes or umbels. Bracts and bracteoles absent. Pollination by ?insects and bats. Flowers stalked. Floral disc absent; nectaries present on the perianth. Perianth regular, of at least 2 dissimilar whorls. Epicalyx present or absent. Calyx segments free or fused, with 5 sepals or lobes, open in bud; calyx urn-shaped, herbaceous. Corolla segments fused, with 5 (–7) lobes, alternating with the sepals or calyx lobes, imbricate in bud; corolla bell-shaped; white, cream, yellow or red, without contrasting markings, membranous; lobes ±entire. Fertile stamens 5–numerous, not clearly correlated with the sepals or calyx lobes, at least partly fused to the corolla, free of the ovary and style, fused by their filaments into an open or closed tube, all ±equal. Anthers dorsifixed, not versatile, opening apparently outwards by longitudinal slits; 1–2-celled. Ovary superior and sessile. Carpels 2–5 (–8), fused; ovary with 2–5 (–8) locules. Style terminal, single and unbranched or single and branched above. Ovules 2–numerous per locule, stalked; placentation axile. Fruit ±fleshy, dehiscent or indehiscent; a loculicidal capsule, or melon-like; the perianth on the maturing fruit deciduous. Disseminule macro-surface with straight hairs or winged; micro-surface ±smooth or lepidote, grey, dull. Seeds 2–numerous per fruit. Aril present or absent. Cotyledons 2. Embryo curved or sharply bent.
(Note: this description has been generated from the coded data compiled for the key. Any errors in the key data will be reflected in the descriptions.)

A treatment of the family Bombacaceae has not yet been published in the Flora of Australia. It will appear in Volume 7.

Australian genera of Bombacaceae (as recognised for the Flora of Australia)


Adansonia gregorii (fruit)
Photo: M.Fagg © M.Fagg 

Adansonia gregorii (habit)
Photo: M.Fagg © M.Fagg 

Bombax ceiba (flower)
Photo: M.Fagg © ANBG