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.

usually well-branched, 25–120 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, basal 7–11 × 0.1–2.3 cm, blade lyrate;

cauline 1–9.5 × 0.1–2.3 cm, blade narrowly lanceolate to linear, margins sinuate-dentate, undulate.

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 at sunset;

floral tube 6.5–14 mm;

sepals 11–21 mm;

petals white, fading pink to red or sometimes purple, elliptic-obovate, 10–15 mm;

filaments 6–9 mm, anthers 2–6 mm, pollen 90–100% fertile;

style 16–32 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.

ovoid, narrowly 4-winged, furrowed between angles, 4.5–8 × 2–5 mm, abruptly tapering to stipe 0–1 mm;

sessile.

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

(1 or)2–4(or 5), yellowish to light brown, 2–3 × 1 mm.

= 14.