Flora of North America species comparison

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

4-16 dm, densely to sparingly 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 copiously prickly on veins and intervein surfaces to sparingly prickly on main veins only;

basal lobed ca. 1/2 distance to midrib, lobe apices usually distinctly rounded, marginal teeth usually less than 1 mm;

distal usually definitely 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 oblong to ellipsoid to obovoid, body 12-22 × 10-16 mm, prickly;

sepal horns terete, flattened or angular in cross section, (4-)6-8(-10) mm, unarmed to densely prickly.

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.

5-10(-13) cm broad, not closely subtended by foliaceous bracts;

petals white;

stamens 150-250;

filaments pale yellow;

pistil 3-5-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.

ovoid, ellipsoid, or lanceoloid, 35-55 × 9-15(-18) mm (including stigma and excluding prickles), prickly, longest prickles to 10 mm, widely spaced, or shorter, more numerous, and interspersed with still shorter prickles, surface then partially obscured.

1.6-2 mm.

1.8-2.6 mm.