Flora of North America species comparison

arising at slightly different heights, not forming just 1 rosette, green, ternate-1–2-pinnately dissected;

petiole sheathing basally to entire length, glabrous;

blade triangular to rhombic, 6–30 × 2–15 cm, surfaces glabrous;

penultimate segments narrow, usually less than 2 mm wide, ultimate segments 100–400, linear, 3–6(–10) × 0.5–1 mm, margins entire, usually not reflexed, apex acute, callus tips 0.1–0.2 mm, firm but not spinelike, terminal segment 1–15 mm;

cauline leaves 0–1(–2).

subterranean.

1–4 per plant, 1 per stem, ± erect, not inflated, 15–45 cm, exceeding leaves, 1–2(–3) mm wide 1 cm below umbel, glabrous.

1–10 cm wide in flower, 4–15 cm wide in fruit, rays 10–25, spreading, longer ones 4–13 cm in fruit, unequal, glabrous or distally scaberulous;

involucel bractlets 5–14, distinct, broadly elliptic to broadly oblong, or obovate, often abruptly narrowed to an acuminate tip, (1.5–)2.5–10.5 mm, subequal to flowers, margins scarious, not ciliate, deeply dissected, sometimes 2-pinnate, glabrous.

petals light yellow, glabrous;

anthers yellow;

ovary and young fruit glabrous.

2–5 mm, shorter than fruit.

dorsiventrally compressed, oblong to oblong-oval to perfectly elliptic, 7.5–13 × 4.5–7 mm, length/width ratio 1.4–2.3;

wings 0.9–2.2 mm wide, 20–90% of body width, about same color as body, corky-thickened;

abaxial ribs slightly raised;

apex rounded to truncate;

oil ducts obsure.