Trailing herb with stems to 50 cm. Almost hairless leaves are oblong and up to 6 cm long with bluntly pointed tips. Round or oblong spikes of flowers to 8 mm long occur in the joint of the stem and leaf (axil). Bracts surrounding the flowers are 2 to 3.5 mm long and less than 1 mm wide and are papery, white or pinkish and hairless. Flattened broadly heart-shaped fruit to 1 mm long does not open to release seeds (indehiscent).
Alternate leaves and dense clusters of flowers in leaf axils. Spreads vegetatively by rooting at the nodes. The gap between each node is >2.5 cm.
Annual or perennial. Moist lowland areas, margins of swamps and rivers.
Tracheophyta (Vascular Plants)
Magnoliopsida (Flowering Plants)
Source: Atlas of Living Australia
Cakes were made by Aboriginal people from seeds of several Alternanthera species.
Plains Joyweed is an undescribed species in northern Vic on heavy clay soils of the Riverina and Keilor Plains. All the floral parts are longer and thinner than Lesser Joyweed.