Description from Flora of China
Caryopteris mongholica var. serrata Maximowicz.
Subshrubs 30-150 cm tall, aromatic, usually branched from base. Branchlets purple-brown, pubescent when young, glabrescent. Petiole ca. 3 mm; leaf blade linear-lanceolate to linear-oblong, 0.8-4 X 0.2-0.7 cm, papery, abaxially densely gray tomentose, adaxially dark green and puberulent, margin entire or subentire. Cymes axillary. Calyx campanulate, ca. 3 mm, deeply 5-lobed, outside densely gray tomentose; lobes linear to linear-lanceolate, ca. 1.5 mm. Corolla blue-purple, 1-1.5 cm, tube ca. 5 mm, pilose in throat, lower lobe strongly fringed. Stamens and style exserted. Ovary glabrous. Fruit subglobose, glabrous. Nutlets with winged edges. Fl. and fr. Aug-Oct.
Dry open slopes, boulder strewn washes, open canyons; 1100-1300 m. Gansu, Hebei, Nei Mongol, Shaanxi, Shanxi [Mongolia].