Amphibious. Leaves dimorphic in aquatic plants; lower leaves linear, 6–30 mm long, 0.5–1 mm wide, 1-veined, deeply notched at apex; upper leaves spathulate to ovate-rhombic, 3–5 mm long, 1–1.7 mm wide, slightly emarginate, 3-veined, petiolate, rosetted; leaves of terrestrial plants linear-elliptic to elliptic, 1–3-veined. Flowers solitary in axils; bracteoles usually absent; stamen 0.6–1 mm long, shorter than fruit; styles deflexed close to fruit, 1.2–2 mm long, deciduous. Fruit mostly sessile (sometimes with pedicel to c. 15 mm long in lower axils), more or less circular, 1–1.2 mm long and wide, sometimes slightly longer than wide, dark brown to greyish; wing narrow, pale. Flowers Aug.–Jan.; fruits present throughout the year.
*CVU, *DunT, *GipP, *Gold, *GGr, *HSF, *MuF, *NIS, *OtP, *VRiv, *VVP. Widespread weed in Victoria, mainly in the west and north where found in shallow water or on mud. Native to Europe and Greenland.
|Bioregion||Occurrence status||Establishment means|
|Victorian Volcanic Plain||present||naturalised|
|Central Victorian Uplands||present||naturalised|
|Northern Inland Slopes||present||naturalised|
|New South Wales|