Flora of North America species comparison

4-10(-15) dm, sparingly to moderately prickly.

5-8 dm, diffusely branched, often decumbent, copiously long-prickly.

blades: abaxial surface sparingly prickly on main veins, adaxial surface unarmed or sparingly prickly on main veins;

basal and proximal lobed 1/2-4/5 distance to midrib;

distal clasping.

blades: surfaces sparingly long-prickly on veins;

basal and proximal lobed nearly to midrib, lobe length often to 5 times width;

distal not clasping.

buds broadly ellipsoid to subglobose, body 12-18 × 10-16 mm, sparingly to rather closely prickly;

sepal horns terete, 3-6(-10) mm, usually unarmed.

buds ellipsoid-oblong, body 15-18 × 12-15 mm, prickly;

sepal horns slender, terete, 12-15 mm, prickly at base.

5-10 cm broad, closely to more distantly subtended by 1-2 foliaceous bracts;

petals white;

stamens 150 or more;

filaments lemon yellow;

pistil (3-)4-5(-7)-carpellate.

7-10 cm broad;

petals white;

stamens 100 or more;

filaments pale yellow;

pistil 3-carpellate.

oblong, oblong-ellipsoid, or narrowly ellipsoid, 20-40(-45) × 10-15(-25) mm (including stigma and excluding prickles), prickly, surface clearly visible to partially obscured, longest prickles widely spaced, 6-10(-12) mm, sometimes interspersed with smaller ones.

narrowly ellipsoid-oblong, 35-45 × 10-14 mm (including stigma and excluding prickles), closely prickly, longest prickles 8-10 mm.

1.6-2 mm.

ca. 2 mm.