Perennial herb 20–70(–85) cm high; stems erect, simple or branched about midway, terete to angular, purplish, pilose to hispid with retrorse hairs; roots orange. Leaves sessile, erect, opposite, oblong-lanceolate to linear-lanceolate, 10–30 mm long, 2–3.5 mm wide, 1-veined, hispid on both surfaces with usually bulbous-based coarse hairs on thickened margins, fine retrorsely hairy otherwise, margins entire with 2–3 obscure teeth on each side, apex rounded. Inflorescence of terminal spike-like racemes, sometimes lax; flowers solitary in the axils of leaf-like bracts; pedicel 0–0.5 mm. Bracts oblong-ovate to ovate, ± 10 mm long, with 1–3-veins prominent, entire, margins with tubercle-based retrorse hairs, retrorse hairs on the veins, ± glabrous otherwise; bracteoles ovate, 5–18 mm long, acute or obtuse. Calyx 7–8 mm long, 10-veined, ± glabrous to finely and sparsely pubescent with ± retrorse hairs on the margins and veins; lobes 2.5–3 mm, ovate, acute. Corolla pale yellow with purplish veins, about twice the length of the calyx, lobed above with rounded, ± equal lobes. Stamens unequal; filaments glabrous; anthers apiculate. Capsule oblong-ovoid, ± 5 mm long, ± 3 mm in diameter, glabrous.
