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, erect, unbranched, 0.5–1 m, herbaceous;

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.

numerous, evenly distributed, larger distally;

petiole thin, equaling or longer than blade;

tendrils distal, few, short;

blade narrowly ovate, pubescent and not glaucous abaxially, base rounded to truncate, margins convex, apex acute to acuminate.

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

peduncle 0.2–1.5 cm.

3–10, axillary to leaves and bracts, 10–50-flowered, semiglobose;

proximalmost peduncle longer than distalmost.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

tepals 3.5–4.5 mm;

anthers usually shorter than filaments;

ovules (1–)2 per locule.

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

blue to black, globose.

;

rhizomes linear or dense masses of potatolike tubers.

= 26.