Description from Flora of China
Scutellaria nipponica Franchet & P. A. L. Savatier; S. oldhamii Miquel.
Herbs rhizomatous. Stems ± erect, 15-35 cm tall, glabrous or sparsely pubescent on angles, unbranched or few branched from base. Petiole 0.8-4 mm, puberulent or subglabrous; leaf blade ovate-triangular to triangular, 0.5-2.4 cm × 3-12 mm, membranous, adaxially sparsely puberulent, abaxially puberulent only on veins, base shallowly cordate to truncate-cordate, margin irregularly and shallowly 1-3-dentate to subentire and ciliolate, apex obtuse to rounded. Racemes poorly defined, terminal, obliquely spreading upward initially, becoming pendent; bracteoles needlelike, ca. 0.75 mm, inserted at base of pedicels in pairs. Flowers axillary. Pedicel 2-3 mm, appressed puberulent. Calyx 1.8-2 mm, conspicuously veined, ciliolate on veins and margin, to 4 mm in fruit; scutellum ca. 1 mm, to 2 mm in fruit. Corolla white or white with purple on lower lip, 5-6.5 mm, puberulent outside, pilose only on middle of lower lip inside; tube slightly curved; middle lobe of lower lip spreading upward, trapeziform, ca. 1.5 × 2-2.5 mm, apex emarginate; lateral lobes triangular-ovate, slightly longer than upper lip. Nutlets yellow-brown, ovoid, ca. 0.7 × 0.5 mm, tuberculate, adaxially slightly swollen, umbonate near base. Fl. and fr. Jun-Sep.
Streamsides, wet areas in larch forests; 0-300 m. Heilongjiang, Jilin, Nei Mongol, Shandong [Japan, Korea, Russia].