Stem erect or decumbent, light green, sometimes light purple below, 10-30 cm tall, much branched, pubescent or nearly glabrous. Petiole 2-15 mm; leaf blade ovate-rhombic or elliptic, 0.5-3 cm × 3-15 mm, glabrous, abaxially greenish white, adaxially green, base cuneate, margin entire or slightly undulate, apex notched, with a mucro. Flowers unisexual, clustered at leaf axils. Bracts and bracteoles subulate, 1.2-1.5 mm, slightly longer than perianth. Tepals 5, membranous. Stamens 2, rarely 3, slightly longer than perianth; stigmas 3. Utricles oblong, 2-2.5 mm, nearly as long as perianth, ?indehiscent. Seeds reddish brown, ca. 1 mm.

Li et al. (Acta Phytotax. Sin. 40: 383–384. 2002) believed this species to be conspecific with Amaranthus polygonoides Linnaeus, a North American species. However, one of us (Clemants) notes that further study might ally A. taishanensis with A. blitum, from which it seems to differ only by having five sepals. Wu Zhengyi (editor’s note) agrees with Clemants.

* Roadsides, waste places, hillsides. Anhui, Shandong.