Flora of North America species comparison

, branches, and twigs with few lenticels, rarely hairy; short shoots present.

stipules 5+ mm, spiny (on most branches proximal to inflorescences);

petiole to 1.2–5.5 cm, longer than rachis, strigulose or glabrous;

pinnae 2, rachis 8–13(–17) mm;

leaflets 2 per pinna, blades obliquely elliptic or oblong- to ovate-elliptic, 1.8–3(–5.5) × 0.7–1.7(–3) cm, base oblique to slightly semicordate, margins entire, flat, apex usually acute, rarely ± rounded and slightly emarginate, brochidodromous venation more conspicuous adaxially, main vein subcentral, surfaces glabrous, abaxially rarely glabrescent.

primary peduncle terete, axis to 10 cm, pubescent, secondary peduncles to 2 cm, pubescent;

glandular bract present at base.

calyx campanulate, 1.5–2 mm, lobes 0.5 mm, strigulose;

corolla campanulate, to 3–4.5 mm, lobes 5 or 6;

stamens white or dirty cream, tube to 2–3.5 mm;

ovary to 2 mm, pubescent, stipe to 1.8 mm.

recurved to coiled (especially at dehiscence), margin constricted between seeds, 10–20 × 1–1.5 cm, base attenuate, apex cuspidate, without a beak, puberulous, veins reticulate;

stipe less than 1 cm.

spherical capitula, 15–30-flowered.

8–12, slightly pendulous, 7–11 × 6–12 mm;

aril white or pinkish, covering nearly all of seed.

triangular, 0.8 mm, puberulous abaxially.

= 26.