Description

Key Characters:

Growth Form: Perennial herbs from a stout taproot.

Stems: Stems usually several, ascending to nearly erect, 3–10 dm long, conspicuously white woolly pubescent.

Roots:

Leaves: Leaves simple. Opposite. Blades elliptic to ovate–orbicular, 3–7 cm long, 1–4 cm wide. Apex obtuse to rounded. Base very broadly cuneate to truncate or subcordate. Surfaces white woolly pubescent, especially on lower surface. Margins crenate–dentate. Petioles 1–2 cm long. Stipules absent.

Flowers: Flowers in compact, axillary verticillasters; each flower +/- bracteolate. Calyx actinomorphic, cylindrical, 4–5 mm long, 10-toothed, the teeth spinose, ± recurved, subequal, splitting longitudinally, usually persistent or sometimes only ventral 1/2 persistent. Corolla zygomorphic, bilabiate, white, 5–6 mm long, upper lip erect, entire or slightly 2-lobed, lower lip 3-lobed, median lobe usually emarginate; nectary disk often present ab base of ovary, annular or developed on anterior side only. Stamens 4, in 2 pairs, lower pair longer, included in corolla tube; anther sacs divaricate, becoming confluent; anthers dithecal, opening by longitudinal slits. Ovary superior, 2-carpellate, placentation basal-axile; ovules 1 per ovary lobe; style 1; stigmas 2.

Fruit: Nutlets 4; 1-seeded; ovoid; ca. 2 mm long; smooth. Seeds with endosperm absent or scanty and oily.

Ploidy: 2n = 34; 36

Habitat: Naturalized and locally common in dry; disturbed sites.

Elevation Range: 150–1,920 m.