Stems erect to ascending, frequently much branched from base, 5-24 cm tall, short strigose, spreading bristly. Leaf blade spatulate-linear to linear, 1.5-7.5 cm × 2-7 mm, abaxially sparsely bristly only along midvein, adaxially ± strigose or minutely hispid, with intermixed bristles, hairs and bristles discoid at base, base attenuate, margin sparsely short bristly, apex acute. Flowers opposite leaves from lower or middle part of stem upward, or several flowers terminating branches and forming crowded or lax short inflorescences. Calyx 1.8-2 mm, parted nearly to base; lobes narrowly triangular, hirsute outside and along margin, strigose inside. Corolla blue or white, glabrous; tube ca. 1.8 mm; appendages low trapeziform or lunate, ca. 0.3 mm; limb 1.5-2 mm wide; lobes orbicular. Nutlets triangular-ovoid, 2-2.5 × ca. 1 mm, with fine tubercles and short hairs; aperture deltate, 0.9-1.2 mm, on upper part of abaxial surface; attachment scar near base. Fl. Jun-Aug.