Bupleurum microcephalum Diels

This species is used as a regional substitute for the Chinese Medicine “chai hu.” It is similar to Bupleurum malconense but differs in the unbranched rootstock and the narrow, longer leaf blades.

Plants 50–100 cm, biennial. Taproot yellowish-brown, elongate-terete, unbranched. Stem solitary, several-branched above, slender, base purplish-tinged, without fibrous remnant sheaths. Basal leaves numerous, narrowly linear, 16–30 × 0.25–1 cm, thin-papery, abaxially slightly glaucous, 5-nerved, base tapering into petiole, margin white scarious. Cauline leaves shorter, sessile, somewhat clasping. Umbels numerous, 1.2–3 cm across; peduncles and rays very slender; bracts 3–5, very small, 0.2–2 × 0.1–0.4 mm, lanceolate or squamose; rays (3–) 4–6(–9), 7–50 mm, unequal; bracteoles 5, elliptic or spatulate, 1.5–2.5 × 0.5–1 mm, mostly shorter than umbellules in fruit; umbellules 2.5–5 mm across, 6–12-flowered; pedicels 1–1.5 mm. Petals yellow, midvein dark. Stylopodium low-conic, yellow. Fruit ovoid, brown, 2.6–3 × 2–2.2 mm, glaucous, base rounded; ribs inconspicuous; mericarps pentagonal in cross section; vittae 3 in each furrow, 4 on commissure. Fl. Jul–Aug, fr. Aug–Oct.

S Gansu, W Sichuan, SE Xizang.

Among shrubs, open slopes, roadsides; 1400–3200 m.