Citation: Delile, Fl. Egypt.Ill. 50, 148, t. 4 (1813-?early 1814).

Derivation: Named for its resemblance to Peplis, a Northern Hemisphere genus in the family Lythraceae.

Synonymy: Not Applicable

Common name: None

Description:
Terrestrial or aquatic, annual or perennial herbs, at least often gland-dotted, prostrate, with long stolons connecting clusters of short branchlets, rooting at the nodes; leaves opposite, with bases of each pair connected by a ridge across the node, petiolate with the blade floating in aquatic situations, entire.

Flowers scattered or in raceme-like inflorescences, 1 to few in axils of leaves or leaf-like bracts; bracteoles 0; sepals fused into a 5-angled 5-toothed calyx, swelling and persisting about the fruit; corolla with the limb conspicuous or reduced, 2-lipped with the upper lip 2-lobed, the lower lip 3-lobed, .to almost rotate; stamens 4 in pairs of unequal length (outside S.Aust.) or 2, with anthers 1-celled, joined in pairs; stigma a broad irritable flap covering the mouth above the anthers, receptive above, when triggered appressed to the upper corolla lip.

Capsule thin-walled and loculicidal from the apex (outside S.Aust.) or thick-walled and tardily both loculicidal and septicidal from the base upwards; seeds many.

Distribution:  About 7 species, all occurring in Australia, 6 endemic, the other spread between India and North Africa.

Biology: No text

Key to Species:

1. Corolla limb prominent, spreading; plants rarely with abundant fruits
2. Annual with branches to 10 cm long; pedicels 0-2 rarely 5 mm long; seeds 0.4-0.8 mm long; corolla lobes 1-1.5 mm long, white to pink or deep-purple, with the tube and palate red to brown or a deep red-purple	P. muelleri 1.
2. Perennial with branches to 30 cm long; pedicels 2-12 mm long; seeds 0.8-1.5 mm long; corolla lobes c. 1.5-4 mm long, blue, with the tube and palate yellow	P. sp.b 2.
1. Corolla limb reduced, hardly exserted from the calyx; seeds 0.7-1.4 mm long; plants often with clusters of subsessile fruits	P. sp.d 3.

Author: Not yet available