Flora of North America species comparison

annual, erect, 2–5 m, herbaceous, glabrous;

prickles absent.

perennial, climbing, branching, ± woody, glabrous, ± unarmed, to stunted, rigid (shrublike), densely armed;

prickles pale green with dark tips, recurved, flattened, stout, 1–2 mm;

stems (especially in nodal areas) with small, waxlike nodules often connected by arachnoid filaments.

few, disposed distally or evenly distributed, subequal;

petiole shorter than blade;

tendrils absent or rudimentary;

blade oblong, oblong-ovate, or sometimes oval, 2.5–12 × 1.5–7.5 cm, not glaucous, puberulent abaxially, base rounded to slightly cordate, margins entire, apex broadly rounded to obtuse or abruptly pointed.

evergreen, ± evenly disposed;

petiole 0.5–2 cm;

blade variable, dull green, thick, narrowly oblong-elliptic, elliptic-ovate, or oval, conspicuously veined, 2–19 × 0.6–13.5 cm, not glaucous or pubescent, base pointed to rounded to narrowly cordate, margins spinose, or sometimes entire with thick edges, apex abruptly mucronate, spiny, or emarginate.

1–3, proximalmost axillary to bracts, 5–12-flowered.

few to numerous, axillary to leaves, few to numerous-flowered, ± open;

peduncle to 1.6 cm, ± equaling or shorter than subtending petiole.

perianth greenish;

tepals 3–3.5 mm;

anthers shorter than filaments;

ovules (1–)2 per locule.

perianth green;

tepals ca. 1.5 mm;

ovule 1 per locule.

globose, 8–10 mm diam., glaucous.

purplish black, globose, sometimes pointed, ca. 6 mm, not glaucous.

;

rhizomes short.

= 26.