Description

Key Characters:

Growth Form: Annual herbs to 3–4 dm tall, from a taproot.

Stems:

Roots:

Leaves: Leaves simple. Opposite. Blades orbicular to ovate–orbicular, 0.7–2.5(–4) cm long and about as wide. Surfaces inconspicuously hirsute, strigose, or subglabrous. Margins crenate or lobed. Subsessile. Stipules absent.

Flowers: Flowers in relatively few verticillasters, these usually widely spaced, each flower +/- bracteolate. Flowers sometimes cleistogamous. Calyx actinomorphic, cylindrical or campanulate, 5–8 mm long, hirsute, 5-nerved, 5-lobed, lobes about as long as tube, splitting longitudinally, usually persisten or sometimes only ventral 1/2 persistent. Corolla zygomorphic, bilabiate, pinkish purple, 12–20 mm long, upper lip 4–5.5 mm long, entire, lower lip obcordate, ca. 4 mm long, lateral lobes minute, linear; nectary disk often present at base of ovary, annular or developed on anterior side only. Stamens 4, in 2 pairs, lower pair longer; anthers pubescent, dithecal, opening by longitudinal slits. Ovary superior, 2-carpellate; ovules 1 per ovary lobe, placentation basal-axile; style 1; stigmas 2.

Fruit: Nutlets grayish yellow; obovoid; triquetrous; constricted at base; ca. 2 × 1 mm; white tuberculate. Seeds with endosperm absent or scanty and oily.

Ploidy: 2n = 18

Habitat: Single collection made at margin of a parking lot.

Elevation Range: 2140 m.