black swallow-wort

Vincetoxicum nigrum is a perennial, herbaceous vine bearing ovate leaves with pointed tips. The leaves are 3–4 inches (7.6–10.2 cm) long, and 2–3 inches (5.1–7.6 cm) wide, occurring in pairs on the stem. The flowers have five petals, and are star-shaped with white hairs. The flowers range in color from dark purple to black. The fruit of Vincetoxicum nigrum is a slender, tapered follicle that ranges in color from green through light brown and is tightly packed with seeds, each bearing a fluffy pappus to allow distribution by the wind.

Habitat. Vincetoxicum nigrum tends to grow in upland areas and is tolerant to variable light, salt, and moisture levels. In the United States, the vine is often found in abandoned fields, hedgerows, brushy areas, woodlands, river banks, transportation corridors, quarries, agricultural fields, and gardens. In gardens, the plant is seen as a fast-growing weed.

Reproduction. Vincetoxicum nigrum emerges from an underground stem in the spring, and flowers during June and July. Vincetoxicum nigrum is self-pollinating, and follicles form throughout the summer. The number of follicles formed is directly linked to the amount of light the plant receives. If there is a lower level of light, then there are fewer follicles compared to a plant exposed to a higher level of light. …