Herbs, to 1 m tall, unbranched or apically branched. Lateral roots fusiform. Stems quadrangular, grooved, white pilose, pith white. Petiole to 4 cm; leaf blade ovate to narrowly ovate, 5-12 cm, abaxially glabrous or pubescent on veins, base rounded, subtruncate, or subcordate, margin regularly serrate. Thyrses to 30 cm; cymes terminal or axillary; peduncle and pedicels glandular hairy. Calyx ca. 4.5 mm; lobes ovate-elliptic to broadly ovate, apex acute. Corolla outside green, inside purplish brown, 7-8 mm; tube globose-cylindric; lower lip ca. 1.5 mm; upper lip ca. 3.5 mm, lobes rotund and with overlapping margins. Stamens ca. 1.5 mm; filaments compressed; staminode fanlike, ca. 1.5 mm. Ovary 2-2.5 mm. Style slightly longer than ovary. Capsule broadly ovoid, 7-9 mm. Fl. Jul-Aug, fr. Sep-Oct.
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