Description from Flora of China
Scutellaria indica Linnaeus var. japonica (Morren & Decaisne) Franchet & P. A. L. Savatier f. humilis Makino; S. simplex Migo; S. ussuriensis Kudo var. typica f. humilis Kudo.
Herbs rhizomatous perennials. Stems purplish 9-20(-30) cm tall, erect to ascending, ca. 1.5 mm in diam., finely antrorse pubescent, unbranched or branched basally. Leaves in 3 or 4 pairs, ± apically crowded, basal ones deciduous; petiole 1-2 cm, longest basally, short to almost absent apically; leaf blade triangular-ovate to circular-ovate, to 4 × 3 cm, papery, adaxially glabrous, abaxially purplish, glabrous, without glands, veins finely pubescent, base rounded, broadly cuneate to shallowly cordate, margin crenate, apex rounded. Racemes terminal, 3.5-9 cm; bracts purplish, narrowly rhombic to ovate, 2-3.5 mm. Pedicel ca. 1.5 mm, densely glandular puberulent. Calyx ca. 2.5 mm, dilated and to 5 mm in fruit, densely glandular puberulent; scutellum ca. 1.5 mm, to 3 mm in fruit. Corolla red-purple or purple, 1.5-2 cm, sparsely puberulent outside, bent at base, pilose, to 5 mm wide at throat; middle lobe of lower lip ovate, apex emarginate, purple spotted; lateral lobes oblong. Nutlets dark chestnut brown, ovoid, ca. 0.7 mm, tuberculate, adaxially umbonate near base. Fl. Mar-Apr, fr. Apr-May.
Grassy slopes, thickets. Anhui, Jiangsu [Japan].