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.

annual, climbing, branching, to 2.5 m, herbaceous, glabrous;

prickles absent.

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.

evenly distributed;

petiole ± equaling blade;

tendrils numerous, long, functional;

blade lustrous, dark green abaxially, narrowly to broadly ovate, 8–16 × 3.5–9 cm, often with minute, whitish pubescence abaxially mostly on veins, with transparent trichomes, base cordate, margins entire, convex, apex long-acuminate;

leaves on branches with oblong, smaller blade.

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

peduncle 0.2–1.5 cm.

numerous, axillary to leaves, 10–35-flowered, globose;

peduncle equaling or shorter than subtending leaf.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth greenish;

tepals 3.5–5 mm;

anthers shorter than filaments, ovules (1–)2 per locule;

pedicel 0.5–2.2 cm.

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

black, subglobose, 8–10 mm, not glaucous.

;

rhizomes linear or dense masses of potatolike tubers.

= 26.