Flora of North America species comparison

central stem usually erect, usually thickened at base and spongy, branched or unbranched, branches few–several, slender, decumbent to ascending, from base, usually encircling central stem in older plants, 10–40(–100) 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 basal rosette and cauline, rosette usually well developed (except subsp. howellii), basal 5–25 × 1–5 cm, cauline 4–12(–18) × 0.5–4 cm;

petiole 1.5–8 cm;

blade rhombic-obovate, lanceolate, or oblanceolate, margins subentire, dentate, or pinnatifid.

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–several opening per day near sunset;

buds nodding, weakly or strongly quadrangular or fluted in distal 1/2, with free tips 0–9 mm;

floral tube 20–40 mm;

sepals (13–)15–35 mm, not spotted;

petals white, fading pink to deep pink, broadly obovate or obcordate, 15–44 mm;

filaments 8–15 mm, anthers 5–14 mm;

style 35–60 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.

spreading, straight to curved, becoming somewhat woody in age, cylindrical to slightly 4-angled, widest toward base, tapering from base to apex, (15–)30–80 × 1.5–5 mm;

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.

numerous, in 1 row per locule, buff with dark spots or black, narrowly obovoid, 1.5–2.8 mm.

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

= 28.