Australian Tropical Rainforest Plants - Online edition

Amaranthus rhombeus R.Br.

Herb (herbaceous or woody, under 1 m tall)
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Leaves and flowers. © CSIRO
Flowers. © CSIRO
Herbarium sheet. © CSIRO

Brown, R. (1810) Prodromus Florae Novae Hollandiae : 414. Type: v.v.


Plant erect to decumbent, 18-30 cm tall including the inflorescence.


Leaves rhomboid in shape, 10-20 x 15-16 mm, petioles 5-20 mm long. Leaf blades reducing in size towards apex where often 7 x 4 mm, petioles down to 0.5 mm or almost sessile. Petioles grooved on the upper surface.


Inflorescence terminal ca. 6-8 cm long. Initially, 2-3 male and female flowers appear in upper leaf axils, then forming into a terminal inflorescence. Flowers are male or female, 1 x 0.5 mm long. Flowers subtended by 3 bracts or bracteole 1-2.5 mm long, bracts white with a green midrib. Perianth consists of 3 tepals, only just fused at the base. Male flower with 3 stamens; stamen 2 mm long, anther 1.5 mm long, filament 1-1.25 mm long; pollen cream. Female flower with 1 ovule.


Fruit 2 mm long, with styles persistent, perianth lobes also persistent. The top of the fruit falls releasing the black seed, 1 mm diam. Embryo white, C-shaped.


Features not available.

Distribution and Ecology

Occurs in NT along the northern coasts, and in NEQ in the Chillagoe-Mungana area around 500 m altitude.

RFK Code
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