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 to clambering, branching, slender, 2–6 m, woody, glabrous;

prickles scattered, subulate.

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.

deciduous to semievergreen;

petiole 0.5–1 cm;

blade abaxially green, drying to lightly orange-tinted brown, ovate-oblong, to ovate-lanceolate, with 3 prominent veins, thin, 6–10 × 3–7 cm, glabrous or minutely pubescent abaxially, not glaucous, base rounded, subcordate, or, sometimes, cuneate at petiole insertion, margins entire, apex acute, mucronate.

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

peduncle 0.2–1.5 cm.

few to many, axillary to leaves, few-flowered, loose, hemispherical;

peduncle 0.5–2 cm, generally shorter than petiole of subtending leaf.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth brownish yellow;

tepals 3–6 mm;

ovule 1 per locule;

pedicel 0.5–1 cm.

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

bright red to orange, globose, 7–9 mm, shining.

;

rhizomes linear or dense masses of potatolike tubers.

;

rhizomes slender, running.