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 or ascending, usually many-branched, 10–120 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 (but not present at flowering) and cauline, 0.7–6.5 × 0.1–1.5 cm, blade linear to narrowly elliptic, margins entire or remotely and coarsely serrate.

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 4–11(–13) mm;

sepals 5–9(–10) mm;

petals white, fading salmon pink to scarlet-red, slightly unequal, obovate to elliptic-obovate or elliptic, 3–7(–8) mm, abruptly clawed;

filaments 3–6.5(–7) mm, anthers (2.5–)3–5(–5.5) mm;

style 10–22 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 and abruptly constricted to terete proximal part, pyramidal part weakly or strongly angled, not conspicuously bulging at base, 4–9 × (1–)1.5–3 mm;

sessile.

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

(1–)3 or 4, light to reddish brown, 1.5–3 × 1–1.5 mm.

= 14, 28, 42, 56.