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Turneraceae


This small family is native to tropical and subtropical America, Africa, Madagascar and the Mascarene Islands. One species is a weed of disturbed areas such as track and road verges on Christmas and Cocos (Keeling) Islands.

Characteristic features of the family Turneraceae in Australia include:

  • erect, perennial herb or shrub with simple, alternate, toothed leaves, gland-dotted below, and with 2 glands at the base of the lamina
  • flowers solitary and axillary, bright yellow, with the flower-stalks (pedicels) joined to the petioles of their subtending leaves for some distance
  • sepals 5, fused into a short tube; petals 5, free and clawed at the base; stamens 5, adjacent to sepals
  • ovary superior with 3 styles, developing into a 3-valved, silky-hairy capsule

Description

Evergreen shrubs, or annual or perennial terrestrial herbs. Extra-floral nectaries on the leaves. Internal secretions not obvious. Plants with simple, non-glandular, unicellular or uniseriate hairs. Leaves alternate and spiral, cauline if herbs, petiolate. Stipules absent or present, distinct and free from the petiole, scale-like or membranous, falling off early. Lamina simple, symmetric, lanceolate, ovate or elliptic; base cuneate; margins dentate or serrate, ±flat; venation pinnate, with the midrib conspicuous, and the tertiary venation reticulate; surfaces not punctate; herbaceous. All the flowers bisexual. Inflorescence terminal or axillary, consisting of solitary flowers. Bracts absent. Bracteoles present. Pollination by insects. Flowers stalked or apparently sessile. Free hypanthium present. Perianth regular, of 2 dissimilar whorls, imbricate in bud. Calyx segments free, with 5 sepals, herbaceous. Corolla segments free, with 5 petals, alternating with the sepals, yellow, without contrasting markings, membranous; claws present; lobes ±entire. Fertile stamens 5, opposite to the sepals, free of the corolla, free of the ovary and style, distinct from each other, all ±equal. Anthers basifixed, not versatile, opening sideways by longitudinal slits, 2-celled. Ovary superior and sessile. Carpels 3, fused; ovary with 1 locule. Style terminal, branching from the base. Ovules 3–numerous, stalked; placentation parietal. Fruit a dry dehiscent loculicidal capsule; the perianth on the maturing fruit rotting or liquefying. Disseminule macro-surface costate; micro-surface ±reticulate, brown, dull. Seeds 3–numerous per fruit. Cotyledons 2. Embryo straight or curved.
(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 Turneraceae has been published in:
Flora of Australia 50.

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

Turnera


Turnera ulmifolia (flower)
Photo: A.S.George © A.S.George