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 usually present at all nodes;

blade linear, 10–25(–30) × (0.5–)1–1.5 mm, base flat, not clasping, margins eglandular.

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

bract margins without prominent glands.

cymes monochasial, dense, sparingly branched, internodes sometimes all shortened, or long proximally, flowers clustered at inflorescence tips;

bract margins eglandular.

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

0.5–3 mm, scarcely longer in fruit, ascending, 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, narrowly ovate, 3–4 mm, subequal, margins glandular-toothed, surfaces glabrous;

petals widely spreading, yellow, often tinged with orange-red, obovate, (4–)6–7(–10) mm, apex obtuse, slightly erose;

cup yellow, rim with petal attachments set in notches;

stamens exserted;

filaments (4–)6–8 mm;

anthers yellow, dehisced anthers 1.5–2 mm;

ovary chambers 6;

styles 3, yellow, (3–)4–6(–8) mm, exserted.

= 36.

= 36.