银州柴胡 yin zhou chai hu

Plants 25–50 cm, perennial. Taproot long, stout, woody, pale reddish-brown, digitate-branched, thickened at apex. Stems numerous, slender, tinged purple at base, branching above, base without fibrous remnant sheaths. Basal leaves oblanceolate, 5–8 × 0.2–0.5 cm, 3–5-nerved, deciduous, base tapering into long petioles, apex acute, apiculate. Middle leaves short-petiolate. Umbels numerous, 10–18 mm across; bracts 1 or 2, or absent, subulate, ca. 2 mm; rays (3–)4–6(–9), slender, 4–11 mm; bracteoles 5, linear, 1–2 × ca. 0.2 mm, shorter than pedicels in fruit; umbellules 2.5–4 mm across, 6–9-flowered; pedicels ca. 2 mm. Petals yellow, midvein brown. Stylopodium low-conic, pale yellow. Fruit broadly ovoid, dark brown, 2.8–3.2 × 2–2.2 mm; ribs prominent; vittae 3 in each furrow, 4 on commissure. Fl. Aug, fr. Sep.

Dry mountain slopes; 500–1900 m. Gansu, Nei Mongol, Ningxia, Shaanxi.

This species is widely used as a substitute for the Chinese medicine “chai hu.” It resembles both Bupleurum angustissimum and B. bicaule but differs in the following characters: root horizontal, smooth; leaves oblanceolate, thinly papery; cauline leaves tapering at base, petioles conspicuous; bracteoles shorter than pedicels in fruit.