Lepidium orbiculare (??naunau) is a small, perennial, many-branched shrub in the mustard family (Brassicaceae) (St. John 1981, pp. 371–373; Wagner et al. 1999, p. 409, Wagner 2020, unpubl. data). It is more than 12 inches (in) (33 centimeter (cm)) tall with glabrous young shoots; leafy branchlets are 0.04 to 0.1 in (1 to 3 millimeter (mm)) in diameter and dark purple in color. Older stems are 0.1 to 0.2 in (3 to 6 mm) in diameter and purplish in color. Leaves are crowded at the ends of the branches; slightly fleshy, glabrous and slender petioles (stalks that attach the leaf blades to the stems) are 0.6 to 1 in (15 to 25 mm) long. Blades are 1.7 to 3 in (4.5 to 7.5 cm) long, 0.7 to 1 in (1.9 to 2.9 cm) wide and green in color. Four sepals are 0.03 in (0.8 mm) long, ovate to broadly oblanceolate, thickened and puberulous in the center but the broad margins are white and membranous. Four white spatulate shaped petals are 0.03 in (0.8 mm) long; six stamens are exerted with filaments 0.03 in (1 mm) long and anthers are 0.08 in (0.2 mm) in diameter. The orbicular shaped ovary is 0.3 in (0.7 mm) long. Seeds are 0.05 to 0.06 in (1.3 to 1.7 mm) in diameter, orbicular, flat, shiny reddish brown with a pale membranous wing 0.004 in (0.1 to 0.2 mm) wide (St. John 1981, pp. 371–372; Wagner 2020, unpubl. data)