Annual herb, erect with ascending branches or with spreading to decumbent branches, up to 45 cm high; indumentum of curved and straight hairs or very rarely with curved hairs only. Leaves sessile, linear or oblanceolate, 7–35 mm long, 1–3 mm wide; apex acuminate or acute, mucro c. 0.3 mm long. Inflorescence supra-axillary, a raceme to 125 mm long, usually not exceeding the leaves, sometimes longer. Pedicel to 4 mm long. Alae deflexed to reflexed in fruit (position), herbaceous, ovate or elliptic, dimidiate to falcate, 5.0–7.8 mm long, 1.4–3.3 mm wide, glabrous or with scattered minute curved hairs or a few marginal cilia or glabrous. Corolla purple; floral appendages fimbriate; upper petal claw 0.5–0.6 mm wide. Stamens terminate at stigma, monadelphous; staminal flap