Thorny amaranth

Amaranthus spinosus, the spiny amaranth, is an erect, branching annual herb of the amaranth family, 30 to 100 cm tall, with smooth, often reddish, angular stems. Its diagnostic feature is a pair of sharp, slender spines borne at the base of each leaf-stalk. The alternate leaves are ovate to rhombic-lance-shaped, long-stalked, and entire. Minute greenish flowers are crowded into slender, branched terminal spikes and dense axillary clusters, the male and female flowers separate on the same plant. The fruit is a small membranous capsule containing a single shiny black seed. A pantropical weed of probable American origin, it grows abundantly on waste ground, roadsides, fields, and disturbed soils throughout warm regions, where its young leaves are gathered as a potherb despite the troublesome spines.