Up to 1 m tall. Leaves in many shades of green, most with toothed edges. Characteristic square stems. Tiny purple, pink, or white flowers form spikes above the leaves in mid- to late summer.
最高1米。葉子呈多種綠色,大多邊緣成小鋸齒狀。莖呈方形。在中至晚夏,細小紫色、粉紅色或白色的花在葉子上方組成尖狀花組。