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.

erect or climbing, usually prickly, sometimes unarmed.

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.

opposite or alternate, prominently 3-veined, reticulate between veins, usually bearing tendrils, usually leathery.

umbellate [or racemose or spicate].

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

peduncle 0.2–1.5 cm.

perianth green;

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

ovule 1 per locule;

pedicel 0.2–1 cm.

unisexual, staminate and pistillate on different plants;

tepals 6, distinct, rarely united into perianth tube;

stamens 2–3-whorled, anthers 1-locular; pistillate flowers bearing staminodes, pistil 3-carpellate;

ovary 2-locular, 1–2 ovules per locule.

baccate.

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

1–3.

;

rhizomes linear or dense masses of potatolike tubers.