Black Swallowwort

Asclepiadaceae

LIFE FORM: Perennial

NATIVITY: Europe

VEGETATIVE CHARACTERISTICS:

This plant climbs on other vegetation and can grow up to 6 feet long.

FLOWERS:

Small clusters of purple-black flowers produced from June through September.

FRUIT/DISPERSAL AGENTS:

Slender, green seed pods are 2 to 3 inches long and filled with numerous seeds with silky, white hairs that facilitate wind-dispersal.

ECOLOGICAL PREFERENCE:

Neglected residential and commercial landscapes; minimally maintained public parks and open space; vacant lots and rubble dump sites; woodlands that develop on abandoned open space; small-scale pavement openings (tree pits) and cracks; chain-link fence lines; rock outcrops and stone walls; unmowed highway banks and median strips with frequent salt applications.

ENVIRONMENTAL FUNCTION:

Disturbance-adapted colonizer.

CULTURAL SIGNIFICANCE:

Once established in the crown of landscape shrubs, this plant is difficult to eradicate and spreads rapidly by seed. Included by Greek physician Pedanius Dioscorides in his five volume herbal, De Materia Medica, which was written in the first century AD and remained in active use into the 1600s. Invasive species in minimally managed habitats.