Flora of North America species comparison

alternate;

stipular glands very inconspicuous, present at proximal nodes, absent distally;

blade linear or narrowly oblong, 10–13(–20) × 2–2.5 mm, base flat, not clasping, margins without stalked glands.

alternate;

stipular glands only at proximal nodes, inconspicuous, or absent;

blade ± linear, 10–20(–30) × 1–2(–3) mm, base flat, not clasping, margins without stalked glands.

cymes monochasial (scorpioid or helicoid), open, branches unequal (main axis obvious), internodes long, flowers widely scattered;

bract margins without prominent glands.

cymes mostly monochasial (scorpioid or helicoid), open, internodes long, flowers widely scattered;

bract margins without prominent glands.

5–25 mm, scarcely longer in fruit, spreading at angles 70–80(–90)°, scarcely bent at apex.

0.5–2(–3) mm, to 6 mm in fruit, spreading at 45° angle, not bent at apex.

sepals erect or reflexed at tip, lanceolate, 1.5–2.5 mm, usually equal, sometimes one larger, marginal glands absent or minute, surfaces glabrous;

petals not or slightly spreading at anthesis, yellow, often with reddish or orange streak on midvein, oblanceolate, sometimes obovate, 0.5–2.5(–4) mm, apex notched or erose;

cup yellow, rim with petal attachment protruding prominently in sinus or strongly indented;

stamens included;

filaments 1–2 mm;

anthers yellow, dehisced anthers 0.5–0.8(–1.2) mm;

ovary chambers 6;

styles 3, yellow, 0.5–1(–1.8) mm, included.

sepals erect, ± spreading at tip, lanceolate, 2–3 mm, equal, marginal glands tiny, surfaces glabrous or with hoary microscopic puberulence;

petals widely spreading, distal 1/2 ± recurved, light or bright yellow, veins sometimes ± red, obovate, 3.5–5.5 mm, apex often deeply notched;

cup yellow, rim hairy, rim with petal attachment in shallow sinus;

stamens exserted;

filaments 3–4 mm;

anthers yellow, dehisced anthers 1.2–1.4 mm;

ovary chambers 6;

styles 3, yellow, 3.5–4.5(–5) mm, exserted.

= 36.

= 34.