Flora of North America species comparison

usually procumbent, sometimes ascending.

prostrate, decumbent, or semi-erect.

blades obovate to obcordate, 2–7(–12) × 2–5(–10) mm, margin serrate on distal 1/3.

blades elliptic, ovate, or obovate, 10–20 × 6–15 mm, margins serrate on distal 1/2.

1- or 2-flowered, usually 1 ripe pod remaining on peduncle, umbels or racemes.

(5–)15–50-flowered, cylindrical heads.

2–4 mm;

calyx pubescent, hairs eglandular, lobes mostly equal to tube;

corolla yellow, slightly longer than calyx.

2–4 mm;

calyx pubescent, hairs eglandular or glandular, lobes equal to tube;

corolla yellow, 2 times length of calyx.

with 2.5–4(–5) coils, short-cylindrical, 2–4(–5) × 2–3 mm, usually pubescent with eglandular hairs, rarely glabrescent, margin prickly, prickles often relatively thin and flexible, base 2-rooted, 1 root arising in dorsal suture, other in submarginal vein;

faces soft, coil face with very strongly curving radial veins that branch slightly and enter broad lateral vein near dorsal suture.

± ovoid, 2–3.5 × 1 mm, covered with eglandular hairs, sometimes also gland-tipped hairs when young;

face with somewhat fusing, prominent veins sometimes appearing as ridges from ventral suture obliquely to dorsal suture.

yellow or brownish yellow, reniform, 1.7–2.4 × 0.9–1.3 mm;

radicle usually slightly less than 1/2 seed length.

1, yellow to olive green, oval to reniform, 1.5–2 × 1–1.15 mm.

margins dentate, incised, or lacerate.

margins entire or irregularly toothed.

= 14.

= 16, 32.