Flora of North America species comparison

perennial, climbing, branching zigzag, terete, 5–9 m × 5–8 mm, woody, glabrous;

prickles numerous, sparse or absent distally, flattened, rigid, stout, to 4 mm.

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.

evergreen;

petiole 0.5–1.2 cm;

blade green abaxially, drying to brownish green, narrowly ovate to ovate-elliptic, with 3 prominent veins, secondary veins obscure to prominent, 4.5–6(–8.5) × 2–3.5 cm, not glaucous, glabrous or minutely pubescent abaxially, base auriculate, pandurate, or rounded, cuneate at insertion of petiole, margins entire, apex acute to abruptly deflexed point.

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.

3–8, terminal, axillary to leaves, 5–8(–25)-flowered, loose;

peduncle 0.2–1.5 cm.

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

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

perianth green;

tepals: staminate 6–8 mm, pistillate 3–4 mm;

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth green;

tepals ca. 1.5 mm;

ovule 1 per locule.

purplish maroon, purple, or black, ovoid to flattened, 5–7 mm, glaucous.

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

;

rhizomes linear or dense masses of potatolike tubers.

;

rhizomes short.