Annual herb; stems erect or lax, usually not branched, dark reddish, to c. 25 cm tall, glandular-hairy and viscid in upper part. Lvs petiolate, usually pinnate or ternate, sometimes simple. Lamina with large terminal lobe to 3.5 cm long, lanceolate to ovate, hairy or glandular-hairy, serrate; base often with 1-4 small irregular lobes or pinnae. Bracts similar to lvs. Fls pedicellate, few in terminal cymes. Calyx 6-8 mm long, deeply lobed, strongly veined; lobes ovate, usually serrate, glandular-ciliate. Corolla golden yellow; lower lip 10-15 mm long, suborbicular; upper lip 3-4 mm long. Stamen connective 1-1.2 mm long, > filaments; posterior (upper) anthers fertile, oblique, situated within upper lip; anterior (lower) anthers sterile, rudimentary, within lower lip. Capsule 6-9 mm long, ovoid. Seeds reddish brown, longitudinally furrowed.