Flora of North America species comparison

(0.3–)2–4(–5) dm, lengths (1–)2–4 times basal leaves.

mostly ascending to erect, not flagelliform, openly branched, not rooting at nodes, (0.5–)1–5(–7) dm.

pinnate to subpinnate, (3–)5–15(–25) cm;

petiole 1–10(–15) cm, long hairs abundant to dense, tightly appressed, 1–2.5 mm, stiff, short hairs absent or obscured, crisped-cottony hairs absent or sparse to common, glands absent or obscured;

leaflets not conduplicate, lateral ones evenly (to unevenly in argyrea phase) paired, (2–)3–6(–7) per side on distal (1/6–)1/5–1/2 of leaf axis, distal pairs ± decurrent, often confluent with terminal leaflet, larger leaflets oblanceolate or narrowly obovate to oblong, 1–5(–6) × 0.3–1.5 cm, distal (2/3–)3/4 to whole margin incised 1/2 or less (rarely more) to midvein, teeth (5–)7–12(–18) per side, 1–4 mm, surfaces ± to strongly dissimilar, abaxial white, long hairs abundant (mostly on, but not limited to, veins), 1–2 mm, stiff, short hairs absent or obscured, crisped-cottony hairs abundant to dense, glands absent or obscured, adaxial green to grayish, long hairs sparse to common, rarely absent, short or crisped to, sometimes, cottony hairs absent or sparse to common, glands sparse.

ephemeral, usually ternate, 2–15 cm;

petiole (1–)3–13 cm, long hairs sparse to common, appressed, 0.5–1 mm, stiff, glands absent;

leaflets 3(–5), central ± obovate to cuneate, (0.5–)1–2 × (0.3–)1–1.5 cm, distal 1/2–2/3 of margin incised ± 1/3 to midvein, teeth 2–4 per side, surfaces similar, green (abaxial sometimes paler), glabrate or sparsely to moderately hairy.

1–2(–3).

(0–)1–3(–7) proximal to 1st flowering node, expanded at anthesis, usually ternate, rarely palmate (or appearing so because of leafletlike stipules), (0.5–)1–3 cm;

petiole usually 0 cm;

leaflets 3(–5), usually much narrower than those of basal leaves, narrowly cuneate to oblanceolate, (0.5–)1–3 × (0.2–)0.5–1 cm, distal 1/3–2/3 of margin incised ± 1/2 to midvein, teeth 2–4(–6) per side, apex usually obtuse to acute.

10–30-flowered.

3–30-flowered, cymose, open.

0.3–3(–5) cm.

(1–)2–3(–5) cm.

epicalyx bractlets narrowly elliptic to lanceolate, rarely linear, 2–5 × 0.5–1.5 mm, (1/2–)2/3 as long as sepals, abaxial vestiture similar to or ± sparser than sepals, usually not glabrescent, straight hairs ± abundant, crisped to sometimes ± cottony hairs absent or sparse to abundant;

hypanthium 3–7 mm diam.;

sepals 4–5.5(–6.5) mm, apex acute to acuminate;

petals 4–8 × 4–7 mm;

filaments 0.5–2.5 mm, anthers 0.6–1.1 mm;

carpels (5–)10–30, styles 1.7–2.5 mm.

4(–5)-merous;

epicalyx bractlets ovate to narrowly elliptic, 1.5–4 × 0.5–1 mm, much smaller than to sometimes equal to sepals;

hypanthium 1.5–2.5 mm diam.;

sepals (2–)3–5 mm, apex broadly acute;

petals (2–)4–6 × (1.5–)3–6 mm, apex ± retuse;

stamens 15–20, filaments 2–3.8 mm, anthers 0.4–0.6 mm;

carpels 4–8(–20), styles 0.9–1.4 mm.

1.4–1.8 mm, smooth to faintly rugose.

1.2–2 mm, rugose.

erect to horizontal, irregularly thickened, 1–8 cm.

= 42, 70, 77, 84, 98.

= 28 (Eurasia).