Description: Perennial or annual herbs, sometimes aquatic, prostrate, with stolons connecting clusters of short branchlets, rooting at nodes; often gland-dotted.
Leaves opposite, lamina floating in aquatic situations, margins entire; petiolate, joined across the node.
Inflorescences solitary-flowered or raceme-like, with 1–several flowers clustered in the axils of leaf-like bracts; bracteoles absent. Calyx tubular, 5-angled, 5-toothed, swelling in fruit. Corolla 2-lipped, often appearing almost rotate; tube symmetrical at the base; upper lip 2-lobed; lower 3-lobed, sometimes with a palate behind. Stamens [4] or 2; filaments not spurred; anthers of pair(s) fused, 1-locular; staminodes absent. Stigma with 1 small vestigial flap and a broad irritable flap, covering the corolla mouth, receptive above, when triggered appressed to the upper corolla lip.
Capsule [thin-walled and loculicidal from the apex] or thick-walled and tardily both loculicidal and septicidal from the base upwards; seeds many, not winged, longitudinally furrowed.
Distribution and occurrence: World: c.4 species. Mostly subtropical, arid and semi-arid Australia, with P. maritimum extending to North Africa, India. NSW Qld SA WA NT.
Text by W. R. Barker
Taxon concept:
| One species in NSW: Peplidium foecundum |
|
