Flora of North America species comparison

ascending to erect, 1–several from base, these unbranched to well-branched, 10–60 cm.

ascending to decumbent, several-branched from base, usually also irregularly branched distally, sometimes with a single, unbranched stem, 20–60(–120) cm.

in a weakly developed basal rosette and cauline, 2–7 × 0.2–1.5 cm, axillary fascicles of reduced leaves often present;

blade oblanceolate to oblong, margins usually pinnatifid, sometimes proximal ones coarsely few-toothed.

in a basal rosette and cauline, 0.5–7.5(–9.5) × 0.1–2.2 cm, blade narrowly lanceolate to elliptic, margins subentire or shallowly sinuate-dentate.

1–3 opening per day near sunset;

buds nodding, weakly quadrangular, without free tips;

floral tube 10–25 mm, mouth conspicuously pubescent, closed with straight, white hairs, 1–2 mm;

sepals 10–20 mm;

petals white, fading pink, ovate or shallowly obcordate, 10–15(–20) mm;

filaments 10–15 mm, anthers 4–7 mm;

style 17–42 mm, stigma exserted beyond anthers at anthesis.

4-merous, zygomorphic, opening near sunset;

floral tube 4–14 mm;

sepals 7–11(–14) mm;

petals white, fading red, slightly unequal, elliptic, 6–10 mm, clawed;

filaments 4–8.5 mm, anthers 3–6 mm, pollen 90–100% fertile;

style 12–26 mm, stigma exserted beyond anthers at anthesis.

ascending to erect, straight, fusiform, weakly 4-angled, 10–20 × 3–5 mm, dehiscent 1/2 their length;

sessile.

erect, pyramidal in distal 1/2, conspicuously bulging at base of distal pyramidal part, strongly 4-angled, conspicuously bulging at base, abruptly constricted to terete proximal part, 7–13 × 3–5 mm;

sessile.

in 2 rows per locule, ellipsoid to subglobose, 1.5–2 × 1.2–1.5 mm, surface regularly pitted, pits in longitudinal lines.

(2 or)3 or 4(–8), reddish brown, 2–2.5 × 1–1.3 mm.

= 14, 28.

= 28.