Plants 5–15 dm, glabrous, glaucous or not.
Leaves 10–30 cm, thin, glabrous but occasionally with scattered hairs on veins on underside; leaflets lanceolate to ovate, 1.5–5(6) cm.
Inflorescences peduncles 10–40 cm; rays 5–40, 2–9 cm; involucel bractlets 0(1–3), inconspicuous; pedicels 1–7 mm.
Flowers ovaries hairy.
Fruits oblong to ovate, 4–7 mm.
2n=22.
Wet meadows, roadsides, wooded areas. Flowering Jun–Aug. 500–1800 m. BW, Col. WA. Native.
See A. arguta discussion.