Families of Flowering Plants of Australia

Austrobaileyaceae

There are only two species in the genus Austrobaileya (the only genus in this primitive family) and both are endemic to the rain forests of north Queensland, A. scandens on the edge of the Atherton Tableland and A. maculata in the Mt. Lewis area.

Characteristic features of the family Austrobaileyaceae in Australia include:

woody lianes with twining stems
leaves opposite
flowers solitary in leaf axils, malodorous, with the floral parts spirally arranged, each with 10-15 greenish perianth parts, 12-25 flattened, petal-like stamens with 4-celled anthers and 8-9 unfused carpels
fruit an orange-yellow berry with several, leathery-coated seeds

Description

Evergreen woody vines climbing by twining stems. Internal secretions not obvious. Plants glabrous. Leaves opposite, petiolate. Stipules absent, or present and distinct and free from petiole; scale-like or membranous or green and leafy; falling off early. Lamina simple, symmetric, lanceolate, ovate, elliptic or oblong; base cuneate or rounded; margins entire, ±flat; venation pinnate, with the midrib conspicuous, and the tertiary venation reticulate or not; surfaces not punctate; leathery. Plants with all the flowers bisexual. Inflorescences axillary, consisting of solitary flowers. Bracts and bracteoles absent. Pollination by ?insects. Flowers malodorous; stalked. Floral disc absent. Perianth regular, of 1 whorl only or all whorls ±similar, with 10–15, free, sepaloid or petaloid segments, outer segments imbricate in bud, magenta, purple, violet or green, with or without contrasting markings (e.g. streaks, spots, etc.); inner perianth parts herbaceous. Fertile stamens 12–25, not clearly correlated with the outer perianth lobes, free of the inner perianth lobes, free of the ovary and style, distinct from each other, all ±equal. Staminodes present. Staminal filaments distinctly flattened. Anthers basifixed, not versatile, opening inwards by longitudinal slits; 4-celled. Ovary superior and sessile. Carpels 8–9, free. Style terminal, single and branched above. Ovules 8–14 per locule, sessile; placentation laminate. Fruit fleshy, indehiscent, berry-like (baccetum); the perianth on the maturing fruit deciduous. Disseminule micro-surface ±smooth, yellow or orange. Seeds 3–4 per fruit. Aril absent. Cotyledons 2. Embryo round or shapeless.
(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 Austrobaileyaceae has not yet been published in the Flora of Australia. It will appear in Volume 2.

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

Austrobaileya