Flora of North America species comparison

usually 1 per caudex branch, arising from center of rosette near ground surface, 1–4.5 dm, densely pubescent proximally, trichomes sessile, 2–4-rayed, 0.15–0.5 mm, glabrous distally.

usually 1 per caudex branch, arising from center of rosette near ground surface, 2–8(–10) dm, usually glabrous proximally, rarely sparsely pubescent, trichomes simple, to 0.7 mm, glabrous distally.

blade oblanceolate, 5–15 mm wide, margins denticulate, ciliate proximally, trichomes (simple), to 1 mm, surfaces moderately pubescent, trichomes subsessile, (2- or) 3–7-rayed, 0.1–0.3 mm.

blade oblanceolate, 3–8(–13) mm wide, margins entire or denticulate, ciliate, trichomes (simple), 0.5–1.2 mm, surfaces sparsely to densely pubescent, trichomes simple, to 0.8 mm, often mixed with short-stalked, 2- or 3-rayed ones, 0.15–0.5 mm.

4–15, not concealing stem;

blade auricles 1–3.5 mm, surfaces of distalmost leaves glabrous.

6–30(–45), often concealing stem proximally;

blade auricles 1–1.5 mm, surfaces of distalmost leaves sparsely pubescent, sometimes margins ciliate.

11–41-flowered, usually unbranched.

10–30(–50)-flowered, usually unbranched.

divaricate at anthesis;

sepals pubescent;

petals white, 6–7 × 1–2 mm, glabrous;

pollen spheroid.

pendent at anthesis;

sepals pubescent;

petals white, 3–4 × 0.7–1.2 mm, glabrous;

pollen ellipsoid.

horizontal to slightly descending, curved to straight, 3–8(–14) mm, glabrous or with some subappressed, branched trichomes.

reflexed, abruptly recurved at base, otherwise straight, 4–10 mm, glabrous.

horizontal to slightly descending, not appressed to rachis, secund, straight, edges parallel, 3–6 cm × 1.5–2 mm;

valves glabrous;

ovules 56–94 per ovary.

strongly reflexed, usually appressed to rachis, not secund, straight, edges parallel, 5–9 cm × 1.8–2.5 mm;

valves glabrous;

ovules 46–80 per ovary;

style 0.2–0.8 mm.

uniseriate, 1.2–1.5 × 1–1.3 mm;

wing continuous, 0.1–0.15 mm wide.

uniseriate, 1.8–2.1 × 1–1.5 mm;

wing continuous, 0.15–0.25 mm wide.