Citation: Orch., Brunonia 8:203 (1986).

Synonymy: M. propinquum sensu J. Black, Fl. S. Aust 646 (1952), in part, auct. non Cunn. (1839).

Common name: None

Description:
Perennial aquatic or marsh-inhabiting herb 5-40 cm tall; leaves dimorphic, submerged leaves in whorls of 4 or 5, crowded, orbicular, pectinate, 18-25 mm long, with 16-27 pinnae (absent in terrestrial plants); emergent leaves in whorls of 3 or 4 (rarely 5) with usually some irregular, linear to terete, 5-15 mm long, entire; in terrestrial plants all leaves intermediate between submerged and emergent types.

Plants monoecious, flowers unisexual, solitary in the axils; bracteoles ovate, in male flowers 0.8-1.2 mm long, tip acute, margins entire or erose; in female flowers smaller; male flowers 4-merous, sessile; sepals linear to lanceolate, 0.9-1.1 mm long, tip acute to obtuse; petals reddish, 2.5-3 mm long, hooded, tardily caducous; stamens 8, anthers linear; styles 0; ovary vestigial; female flowers 4-merous, sessile; sepals, petals and stamens 0; styles 4, elongate, tapering, becoming reflexed, stigmas red or pink, fading to white, fimbriate; ovary a deep reddish-purple, subglobose, c. 0.65 mm long, 4-locular.

fruit a deep reddish-purple, more or less cubic; mericarps ovoid, 0.75-0.85 (rarely to 1.1) mm long, widest at the base tapering to an obliquely truncate apex, aculeate-tuberculate.

Published illustration: Orchard (1986) Brunonia 8:, fig. 11.

Distribution:  Although this species can be aquatic it is more frequently found on mud and in seepage areas. S.Aust.: MU, SL, KI, SE.   Qld; N.S.W.; Vic.; Tas. Conservation status: native Flowering time: Sept. — Dec.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: No text

Taxonomic notes: A very polymorphic species which can only be separated satisfactorily from related taxa when fully fertile with flowers and fruits. In S.Aust. it is only readily confusable with M. variifolium from which it differs in having usually some of the upper leaves arranged irregularly, and in its mericarps which are shorter, ovoid instead of cylindrical and reddish-purple instead of yellow-brown. See Orchard (in press) for a detailed discussion of variability and separation from related species.

Author: Not yet available