Flora of North America species comparison

tubers fusiform, thickened.

with glistening sessile-glandular hairs and ± matted-pubescent to villous and hirsute (hairs scattered, erect, stiff, 2–3 mm).

mid cauline stipules ± falcate, margins dentate;

major leaflets 3–15 (mid cauline 9), minor 1–3 pairs;

major leaflet blades ± obovate, terminal largest, largest of these 2.3–4.1 × 1–1.7 cm, margins incised, apex obtuse to acute, abaxial surfaces glistening with sessile-glandular hairs and pubescent to villous and sparsely hirsute (hairs stiff, 2 mm).

alternate, odd-pinnately compound;

stipules persistent (absent in Acaena), adnate to petiole (free in Poterium);

venation pinnate.

axes often with glistening sessile-glandular hairs and pubescent to villous and hirsute (hairs stiff, erect, 2 mm).

usually ± alternate.

perianth and androecium perigynous;

epicalyx bractlets absent;

hypanthium hemispheric, obconic, ovoid, urceolate, top-shaped, ellipsoid, nearly orbicular, or obtriangular;

torus absent;

carpels 1 or 2(or 3), rarely more, styles terminal, distinct;

ovule 1, apical.

achenes, enclosed within enlarged, often hardened, sometimes armed hypanthia;

styles deciduous, not elongate.

hypanthia hemispheric to turbinate, 1.5–2.7 × 1.8–3.3 mm, obscurely sulcate, hooked bristles in 3–4 circumferential rows, proximal row spreading 45–90°, glistening with sessile-glandular hairs (often yellow).