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, immature erect, older climbing, 1–2 m, occasionally branching, 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.

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.

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

peduncle 0.2–1.5 cm.

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.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 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.

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

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

;

rhizomes linear or dense masses of potatolike tubers.

= 30.