Flora of North America species comparison

opposite or fascicled, 1–3 cm, folded at night and often also in heat of day;

stipules persistent, subulate, 1 mm, apex acute, somewhat spinescent, glabrous;

petiole absent or nearly so;

leaflets 8–16, dark green, linear-oblong to linear-spatulate, 5–15 × 2–3 mm, apex obtuse, coriaceous, surfaces reticulate.

hairy.

axillary, mostly solitary, sometimes clustered, 1.2–2 cm diam.;

sepals (4–)5, obovate, to 5 mm, outer smaller;

petals (4–)5, usually blue to purple, rarely white, obovate to elliptic, 6–10 × 2–3 mm, base short-clawed, apex often notched;

stamens (8–)10, shorter than petals;

filaments each with small crenate scale at base;

ovary obcordiform, flattened, 2(–4)-lobed, 2(–4)-locular, hairy;

style subulate.

becoming orange, obcordiform, flattened, 10–20 mm diam., 2(–4)-lobed, 2(–4)-locular, ± 2(–4)-winged, apex abruptly attenuate-apiculate, reticulate, hairy.

yellowish brown, ovoid to reniform, 10–11 mm.