Pyrethrum ambiguum Ledebour, Fl. Altaic. 4: 118. 1833; Chamaemelum ambiguum (Ledebour) Boissier; Matricaria ambigua (Ledebour) Krylov.

Herbs, perennial, 15-50 cm tall, rhizomatous; stems erect, unbranched, striate, scattered pilose below capitula. Basal leaves with petiole base dilated; leaf blade lanceolate-oblong or oblong, 3-7(-10) × 1-2 cm, 2-pinnatisect, both surfaces glabrous; primary lateral segments many paired; ultimate segments linear, sessile, small. Capitula solitary, terminal, 3-4 cm in diam. Involucre hemispheric, 1-1.5 cm in diam.; phyllaries in 3 rows, abaxially glabrous, scarious margin narrow, dark brown, outer phyllaries lanceolate, 6-6.5 mm, middle ones oblong, inner ones oblanceolate. Ray florets white; lamina ca. 2 × 4.5 mm. Disk florets yellow, 5-lobed; lobes each with red apical resin sac. Achenes deep brown, ca. 2 mm, tuberculate, with 1 adaxial and 2 lateral thick whitish ribs, sometimes also 1 or 2 thin abaxial ribs, abaxially and apically with 2 distinct resin sacs. Corona with broad obtuse teeth. Fl. and fr. Jun-Aug.

Sunny mountain slopes, grasslands of river valleys; 700-2600 m. Heilongjiang, Xinjiang (Altay Shan, Tian Shan) [Kazakhstan, Mongolia, Russia; SW Asia].