Annual herb. Stem up to 60 cm. high, erect, simple or branched from the base, puberulous (hairs very short and thin, arcuate, antrorse, subappressed) and sparsely setose (setae c. 0·5 mm. long, yellowish towards the apex, brownish at the swollen base). Leaves all similar, up to 15 × 1·6 cm., oblong-lanceolate to linear-lanceolate, unlobed, tapering towards the base and the very acute apex, shallowly undulate and with minute teeth at the margin, sometimes with some triangular teeth near the base and a pair of sessile glands just at the base, thinly membranous, glabrous everywhere or sparsely puberulous towards the base; petiole 1–2 mm. long to absent. Flowers (4)5–9 per raceme; peduncles up to 25 cm. long, sparsely hairy at the base, glabrous upwards; pedicels c. 2 mm. long in flower, up to 4 mm. long in fruit. Flower-buds acute. Calyx sparsely setose, without hairs; tube 10 mm. long; lobes 5 mm. long, oblong-linear, acute, with a brown seta below the apex. Petals c. 22 mm. long, orange, attenuate-cuneate towards the base, adnate to the calyx-tube for 3·5 mm., the limb c. 9 × 5 mm., rhombic-obovate. Brevistylous flowers: filaments of the longer stamens ±12 mm. long, those of the shorter ones ± 9 mm. long; anthers 3 mm. long. Ovary 3 mm. long; styles 3 mm. long. Capsules up to 5·5 × 0·15 cm., glabrous. Seeds 2·25–3 × 1–1·25 mm.
