Barbara Ertter and James L. Reveal in Flora of North America (vol. 9)
Shrubs, (0.2–) 1–10 (–16) dm; taprooted. Stems: prostrate to erect; bark reddish brown or grayish, shredding; lateral short shoots often present (bearing fascicles of leaves); unarmed; villous first year, then glabrous. Leaves deciduous, sometimes persistent, cauline, alternate, usually ± odd-pinnate to subpalmate (jointed beyond stipules and at distal leaflet node), rarely ternate; stipules persistent, proximally adnate to base of petiole, broadly lanceolate to ovate, margins entire; petiole present; blade ± ovate in outline, 0.5–2.6 cm, foliaceous, leaflets (3–) 5 (–7), linear to narrowly elliptic or oblong, margins flat or revolute, entire, venation pinnate, surfaces glabrous or hairy. Inflorescences terminal and on lateral twigs, solitary flowers or 2–7(–30)-flowered, loosely cymose, glabrous or hairy; bracts present, ±leafy; bracteoles absent. Pedicels present. Flowers occasionally functionally unisexual (plants monoecious), (10–) 15–30 (–35) mm diam.; epicalyx bractlets 5; hypanthium patelliform to cupulate, 1–2 × 3.5–5 mm, villous; sepals 5, spreading, ovate to broadly elliptic; petals 5, yellow (sometimes white), obovate to orbiculate; stamens 20 or 25 (–30), shorter than petals; carpels 30–100, hirsute, styles sub-basal; ovule 1. Fruits aggregated achenes, individually deciduous, 30–100, obliquely ovoid, 1.4–1.8(–2) mm, hirsute; hypanthium persistent; sepals persistent, erect; styles tardily deciduous, jointed. x = 7.
Species within checklist:
NAU Native Plants Fall 2017 Final