Cyclospermum leptophyllum

Slender herb to 70 cm high. Leaves 2.5–4(–10) cm long, oblong-ovate in outline, 3–4-pinnate or ternately dissected; segments filiform, 0.5–1 mm wide; lower leaves petiolate, upper leaves sessile. Umbels 1.5–2.5 cm diam., sessile to shortly pedunculate; rays 2–5, 8–24 mm long; umbellules 8–12 mm diam., usually 6–20-flowered; bracts and bracteoles absent; pedicels 3–7 mm long. Petals white, c. 0.3 mm long. Fruit 1–3 mm long. Flowers spring and summer.