Plants of South Eastern New South Wales
Amaranthus retroflexus
Common name
Redroot amaranth, Redroot
Family
Amaranthaceae
Where found
Weed of paddocks, roadsides, gardens, and disturbed open ground. Mainly in the northern ACT. Widespread but sporadic north from the ACT and in the Sydney area.
Notes
Introduced annual herb to about 1.2 m tall, the base of the stem and the roots red. Bracts and bracteoles below the flowers with spiny tips. Stems angled or grooved, hairy. Leaves alternating up the stems, 2-14 cm long, 10–80 mm wide, hairy, margins usually entire, sometimes wavy and/or toothed to scalloped, tips pointed or with a mucro when young, blunt and notched at maturity. Male and female flowers on the same plant. Flowers greenish turning red to brown, with 5 'petals', each 1.5-3 mm long, mucronate or entire when young, obtuse and notched at maturity, the longest bracts 3-6 mm long. Flowers in dense cylindrical spikes, crowded toward the ends of the branches and at the base of the upper leaves, to about 10 cm long, 1–2 cm diameter.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Amaranthus~retroflexus (accessed 3 January, 2021)
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