Osmorhiza aristata (Thunb.) Rydb.

A broad range of morphological variation can be seen within this species. Taxonomic treatments vary, with some authors recognizing several distinct taxa, whereas others consider this as continuous variation within one undivided species.

Plants 25–70 cm high. Taproot aromatic. Stem green or purplish tinged. Basal leaves petiolate; petiole 5–26 cm; blade to 29 × 25 cm; pinnae 2–4 pairs, ultimate segments ovate to ovate-lanceolate, (0.5–)1–6(–9) × (0.2–)0.5–5(–8) cm, both surfaces hispid or pilose with white hairs, hairs sometimes restricted to veins. Peduncles 4–22 cm; bracts 1–4, subulate to linear, 0.5–1.2 cm, caducous; rays 3–5, 2–5 cm, lengthening in fruit to 10 cm; bracteoles 4–5, lanceolate to ovate-lanceolate, 2–5 × 1–1.5 mm, abaxially pubescent and on margin, usually reflexed. Fertile flowers 1–6 in each umbellule. Petals obovate, ca. 1.2 × 1 mm. Styles slightly longer than the stylopodium. Ovary white pubescent. Fruit 1–2.2 × 0.2–0.25 cm, base caudate; ribs sparsely bristly, densest towards the base. Fl. and fr. May–Jul.

Plants 50-150 cm tall. Root long tapering. Stem glabrous. Leaves biternate, sparsely pubsecent; leaflets oval to ovate, 1-7 cm long; margin coarsely toothed. Involucre of 1 or 2 linear bracts or lacking. Rays 3-5, unequal, 4-8 cm long. Fruit I-2 cm long, fusiform, beaked, bristly; bristles adpressed; stylopodium coni¬cal; styles erect, 1 mm long.

Widely distributed in China [Bhutan, N India, Japan, Kashmir, Korea, Mongolia, Nepal, Pakistan, Russia (Siberia); North America].

Distribution: Central Asia to South West China, India, W. Pakistan.

Forests, grassy places in valleys and on stream banks; 200–3500 m.