Marsh Skullcap

Herbs perennial, rhizomatous. Stems erect, 35-40 cm tall, slightly grooved, glabrous except for sparsely retrorse pubescent angles, leafless basally, much branched upward. Petiole 2-7 mm; leaf blade oblong-lanceolate, 1.5-6 × 0.8-3 cm, larger basally, membranous to papery, pubescent, base shallowly cordate, margin crenate-serrate, apex acute. Flowers axillary on apical part of stem, secund; pedicel ca. 2 mm, densely retrorse pubescent. Calyx ca. 3.5 mm, densely white pubescent outside, to 5 mm in fruit; scutellum ca. 0.8 mm, erect, to 1.5 mm in fruit. Corolla purple to blue, ca. 1.8 cm, glandular pubescent outside, lips partly puberulent; tube base slightly saccate, throat 3.5-5 mm wide; upper lip semicircular, ca. 2.5 mm wide; middle lobe of lower lip triangular-ovate, apex emarginate; lateral lobes oblong, ca. 1.5 mm wide. Nutlets yellow, triquetrous, ovoid, ca. 1 mm in diam., tuberculate, adaxially umbonate at middle. Fl. Jun-Jul, fr. Jul-Aug.

Nei Mongol, Shaanxi, Xinjiang [Japan, Kazakhstan, Kyrgyzstan, Mongolia, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia, Europe, North America].

Alluvial soils; 400-1100 m.