Amaranthus spinosus L.
Common Name : Spiny pigweed Family : Amaranthaceae Habit : An erect, branched, annual or perennial herb, varying in colour from green to purple. Stem : 30-60 cm tall with hard, straight, paired axillary spines. Leaves : Long-petioled, oblong, ovate-elliptic or lanceolate, acute or obtuse, base cuneate, generally 1-6 cm long and 0.5-2.6 cm wide. Flowers : Minute, grayish-green, borne in dense axillary clusters or terminal spikes. Fruits : Dehiscent utricle. Seeds : Oblong, 1.0-1.4 mm long, 0.7-1.0 mm wide, black, compressed, shining.