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, green, often mottled, terete, to 5+ m, woody, glaucous, glabrous;

prickles, when present, thin, 1–5 mm.

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 semi evergreen, ± evenly disposed;

petiole 0.5–1.5 cm;

blade green to glaucous-green, often mottled adaxially, silvery grayish abaxially, drying to brownish tan adaxially, broadly ovate, elliptic to reniform, with 3 (or 5) conspicuous veins, 4.5–11 × 2.5–6.6 cm, glabrous and glaucous abaxially, base truncate, subcordate, or attenuate, margins entire, apex rounded, tapering, or short-acuminate.

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

peduncle 0.2–1.5 cm.

few to many, axillary to leaves, 5–12+-flowered, open, umbellate to hemispherical;

peduncle 2–5 cm.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth yellow to bronze;

tepals 3–7 mm;

anthers longer than filaments;

ovule 1 per locule;

pedicel 0.5–1 cm.

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

blue to black, subglobose, 8–10 mm, shiny black at maturity, glaucous.

;

rhizomes linear or dense masses of potatolike tubers.

;

rhizomes tuberous, or spinose, linear.

= 28, 32.