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Dichapetalaceae


This small family is found throughout the tropics. Only one species reaches Australia, where it occurs in vine thickets and rainforests on eastern Cape York Peninsula.

Characteristic features of the family Dichapetalaceae in Australia include:

  • scrambling shrub or small tree with simple, alternate leaves
  • flowers small, in short axillary panicles, unisexual, with 5 sepals and petals, and 5 stamens alternating with 2-lobed glands
  • ovary superior, densely hairy, developing into a lobed, yellow or orange drupe

Description

Evergreen trees, or shrubs, or woody or herbaceous vines climbing by hooks or scrambling stems. Internal secretions not obvious. Plants with simple, non-glandular, unicellular hairs. Leaves alternate and spiral, or distichous, petiolate. Stipules distinct and free from the petiole, green and leafy, falling off early. Lamina simple, symmetric, elliptic, oblanceolate or obovate; base cuneate or rounded; margins entire, ±flat; venation pinnate, with the midrib conspicuous, and the tertiary venation reticulate; surfaces not punctate or rarely dark-punctate; herbaceous. Male and female flowers occurring on separate plants. Inflorescences axillary or terminal, consisting of cymes. Bracts present. Flowers stalked. Floral disc absent; nectaries present on the perianth. Perianth regular, of 2 dissimilar whorls, imbricate in bud. Calyx segments fused, with 5 lobes, herbaceous. Corolla segments free, with 5 petals, alternating with the calyx lobes, white or yellow, without contrasting markings, membranous; claws absent; lobes notched, emarginate, bifid or bilobed. Fertile stamens 5, opposite to the calyx lobes, at least partly fused to the corolla, free of the ovary and style, distinct from each other, all ±equal. Staminodes present. Anthers dorsifixed, not versatile, opening inwards by longitudinal slits; 2-celled. Ovary superior and sessile. Carpels 24, fused; ovary with 3 locules. Style single and unbranched, or branching from the base, or absent and the stigma ±sessile on the ovary. Ovules 2 per locule, stalked; placentation apical. Fruit a fleshy, indehiscent drupe; the perianth on the maturing fruit deciduous or dry and persistent. Disseminule macro-surface lobed; micro-surface ±smooth, yellow or orange. Seeds 13 per fruit. Aril absent. Cotyledons 2. Embryo straight.
(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 Dichapetalaceae has been published in:
Flora of Australia 22: 218-219.

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

Dichapetalum


Dichapetalum papuanum (fruits)
Photo: B.Hyland CSIRO