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, 0.2–0.6 m, herbaceous, glabrous, glaucous abaxially;

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.

few, approximate distally;

tendrils absent;

blade ovate, 6–15 × 1.5–8 cm; glabrous and glaucous abaxially, base cordate, margins entire, apex acute to acuminate.

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

peduncle 0.2–1.5 cm.

1–few, proximalmost axillary to leaves or bracts, few-flowered, open;

peduncle 5–10 cm.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth greenish;

tepals 2.5–3.5 mm;

anthers longer than filaments;

ovules (1–)2 per locule;

pedicel slender, ca. 1 cm.

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

black to bluish black, globose, ca. 8 mm diam., not glaucous.

;

rhizomes linear or dense masses of potatolike tubers.

= 26.