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, branching, to 2.5 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.

petiole thin, 1–6 cm;

tendrils numerous, long, functional;

blade oblong-ovate, ovate, or round, 4.5–12 × 3–9 cm, glabrous abaxially, base cordate to truncate, margins entire, apex obtuse to acute;

proximal cauline leaves narrower and smaller.

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

peduncle 0.2–1.5 cm.

many, axillary to leaves, 20–100+-flowered, globose;

peduncle to 30 cm, progressively shorter distally.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

perianth greenish, carrion-scented;

tepals 3.5–4.5 mm;

anthers much shorter than filaments;

ovules (1–)2 per locule;

pedicel 0.5–2 cm.

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

blue, subglobose, ca. 10 mm diam., glaucous.

;

rhizomes linear or dense masses of potatolike tubers.

.

= 26.