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.

erect, branched below and just above ground, branched also proximal to inflorescences, (40–)60–250 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 3–13 × 0.6–2.5 cm, blade spatulate to oblanceolate, cauline (1–)2.5–12 × 0.1–1 cm, blade linear to narrowly oblanceolate, margins slightly to conspicuously sinuate-dentate.

slender.

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 3–9 mm;

sepals 6–12 mm;

petals white, fading dark pink to red, slightly unequal, elliptic-obovate, 7–11 mm;

stamens presented in lower 1/2 of flower, filaments 3–7 mm, anthers 2.5–5 mm, pollen 90–100% fertile;

style 9.5–19 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.

lanceoloid to narrowly ovoid, narrowly 4-winged, 7–12 × 1.5–2.5 mm, tapered to a sterile stipe 2–5 mm.

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

(2 or)3 or 4(or 5), light brown or reddish brown, 1.5–2.5 × 0.8–1.3 mm.

= 14.