Flora of North America species comparison

annual, immature erect, older climbing, 1–2 m, occasionally branching, herbaceous, glabrous;

prickles absent.

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.

numerous, evenly distributed;

tendrils numerous, long, functional;

blade deltate-ovate, pandurate, or cordate-ovate, the larger hastate, thin, 5–12 × 2–5 cm, coriaceous, glabrous, glaucous abaxially, base truncate to subcordate;

apex round to cuspidate.

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.

solitary or in sets of 3, axillary to leaves, 10–35-flowered, loose, subglobose;

peduncle shorter than to 1.5 as long as subtending leaf.

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

peduncle 0.2–1.5 cm.

perianth greenish;

tepals 1.5–2.5 mm;

anthers equaling or slightly larger than filaments;

ovules (1–)2 per locule;

pedicel 0.3–1.5 cm.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

blue to black, subglobose, 4–6 mm, glaucous.

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

;

rhizomes linear or dense masses of potatolike tubers.

= 30.