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, branched, 2–3 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, proximalmost reduced to bracts;

petiole shorter than blade;

tendrils numerous, long, functional;

blade dark green, triangular, ovate, or slightly hastate, 2.5–8.5 × 4–7.5 cm, membranous, glabrous and glaucous abaxially, base truncate, cordate, or hastate, lobes rounded;

margins entire;

apex cuspidate.

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

peduncle 0.2–1.5 cm.

axillary to leaves, staminate to 20-flowered, pistillate few–40-flowered, moderately dense, subspherical;

peduncle of staminate umbel ± equaling subtending leaf, pistillate to 13.5 cm.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth light green;

tepals 1.5–2 mm;

anthers slightly shorter than to equaling filaments;

ovules (1–)2 per locule;

pedicel thin, ca. 1.5 cm.

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

blue, ovoid, 6–8 mm.

;

rhizomes linear or dense masses of potatolike tubers.