Description

Key Characters:

Growth Form: Vines.

Stems: Stems twining, herbaceous, up to ca. 3 m long, glabrous.

Roots:

Leaves: Leaves simple, rarely compound. Alternate. Blades cordate, 3.5-6 cm long, 3-5 cm wide. Apex narrowly acuminate to acute, mucronulate. Base acute, cordate to truncate, petiolate, subsessile, or sessile. Surfaces glabrous; blades chartaceous. Margins entire. Petioles up to 8 cm long. Stipules absent.

Flowers: Flowers solitary, axillary, or few in cymes, pedicels 5-40 mm long; bracts scale-like to foliose. Flowers bisexual (perfect), actinomorphic, 5-merous. Calyx of 5 sepals, distinct, imbricate, herbaceous to subcoriaceous, unequal, inner ones ovate, larger than outer ones, ca. 6 mm long, ca. 3 mm wide, apex acute, base rounded, outer ones ca. 5 mm long, ca.2.5 mm wide, apex acuminate, mucronate, base rounded; all sepals glabrous, minutely verrucose, margins scarious; often somewhat enlarging in fruit but not markedly accrescent, persistent, occasionally accrescent. Corolla of 5 fused petals; petals yellow, purple within tube, funnelform, 2.5-4 cm long. Stamens 5, distinct; included or rarely exserted; filaments inserted on corolla tube base alternate with corolla lobes; anthers dithecal, usually linear or oblong, extrorse. Ovary superior, 2–4-carpellate, usually with as many cells, placentation basal or basal-axile; ovules 2(4, 6) per cell, or ovary 1-celled and ovules 4, these erect, anatropous; style 1, filiform, simple or bifid, or sometimes with 2 distinct style; stigma globose or 2–3-lobed, the lobes globose.

Fruit: Capsules brown; ovoid; 1-1.5 cm long; 0.5-0.7 cm in diameter; glabrous; dehiscent by 4 valves or rarely 6 valves; or splitting irregularly. Seeds often 4; sometimes fewer; black; globose to ovoid; ca. 4 mm in diameter; glabrous to puberulent ; endosperm absent or scanty; cartilaginous; cotyledons usually foliaceous.

Ploidy: 2n = 30

Habitat: Naturalized in disturbed mesic sites.

Elevation Range: 15–600 m.