Trachymene thysanocarpa

Erect, taprooted annual to 60 cm high. Leaves tufted at base and cauline; lamina ternately dissected, 1.5–5.5 cm diam., with segments cuneate and further ternately divided, surfaces sparsely pilose with glandular and/or eglandular hairs; petioles 1–7 cm long, pilose or glabrous (but then margins of sheathing bases ciliate). Umbels several to numerous, often umbellately arranged, 50–120-flowered; peduncle 2–15 cm long; involucral bracts 18–24, linear, 4.3–7.3 mm long, glabrous, rarely ciliate; pedicels 3–13 mm long. Sepals present, 0.2–0.4 mm long; petals ovate or elliptic, 1–1.8 mm long, white; stamens 1.5–2 mm long; styles 0.7–1.5 mm long. Mericarps 3.5–5.5 mm long, 3.2–3.8 mm wide, crenately winged along the dorsal margin, smooth to papillate, often one of some pairs smaller. Flowers Oct.–Dec.