Flora of North America species comparison

usually 3–7 per caudex branch, arising from margin of rosette near ground surface, or arising laterally proximal to sterile shoots, 0.4–2.5 dm, glabrous or pubescent proximally, trichomes simple and short-stalked, 2-rayed, 0.1–0.4 mm, glabrous distally.

usually 1 per caudex branch, arising from center of leaf tufts, elevated above ground surface on woody base, (1.5–)3–7.5 dm, densely pubescent proximally, trichomes short-stalked, usually 4–7-rayed, 0.1–0.3 mm, similarly pubescent distally.

blade linear to linear-oblanceolate, 1–2.5 mm wide, margins usually entire, rarely denticulate, often ciliate, trichomes (simple), 0.3–0.7 mm, surfaces glabrous or sparsely pubescent, trichomes short-stalked, 2- or 3-rayed, 0.1–0.4 mm.

blade linear to linear-oblanceolate, 1–3 mm wide, margins entire, not ciliate, surfaces densely pubescent, trichomes short-stalked, 4–9-rayed, 0.1–0.3 mm.

3–12, not concealing stem;

blade auricles absent, surfaces of distalmost leaves usually glabrous, rarely sparsely pubescent.

10–30, often concealing stem proximally;

blade auricles absent or, rarely, to 0.5 mm, surfaces of distalmost leaves pubescent.

2–12-flowered, unbranched.

8–25-flowered, usually unbranched.

ascending-divaricate at anthesis;

sepals glabrous or pubescent;

petals white to pale lavender, 4–5 × 1.5–2 mm, glabrous;

pollen ellipsoid.

descending at anthesis;

sepals pubescent;

petals usually purple, rarely white, 9–16 × 2–4(–5) mm, sparsely pubescent or glabrous (trichomes scattered abaxially);

pollen ellipsoid.

divaricate-ascending to horizontal, slightly to strongly recurved, 3–8 mm, glabrous or sparsely pubescent, trichomes (isolated), simple.

reflexed, abruptly recurved at base, otherwise straight, 8–16 mm, pubescent, trichomes appressed, branched.

pendent, not appressed to rachis, not or, rarely, weakly secund, straight, edges parallel, 1.5–3.5 cm × 1.2–2 mm;

valves glabrous;

ovules 28–44 per ovary;

style 0.1–0.4 mm.

strongly reflexed, often appressed to rachis, sometimes somewhat secund, straight, edges parallel, 3.3–8 cm × 2.5–4 mm;

valves pubescent throughout;

ovules 68–106 per ovary;

style 0.1–0.3 mm.

uniseriate, 0.9–1.2 × 0.6–1 mm;

wing often continuous, 0.07–0.1 mm wide.

biseriate, 1.7–2.8 × 1.5–2.2 mm;

wing continuous, 0.25–0.65 mm wide.