SPINY AMARANTH, Amaranthus spinosus L. 1, upper portion of plant showing leaves, spines, and flowers; 2, flower; 3, seed. Annual, reproducing by seeds. Stems upright, branched, up to 3 feet (0.9 m) tall, reddish, bearing spines at the bases of the leaf stalks. Leaves alternate, simple, dull green, ovate-lanceolate to ovate. Flowers small, green, in numerous long spikes. Terminal spike often wholly or chiefly staminate; axillary flower clusters mostly pistillate. Seeds egg-shaped, shiny black, notched at one end, about 0.7 to 1 mm wide. Found in fields, gardens, unused yards, and similar places.