Description
A herbaceous perennial vine with twining stems. The leaves are dark green, tapered at the end and between 5-12cm in length. Flowers are star-shaped, dark purple and are visible from late spring to late summer.
Fruits/pods are slender and smooth, between 5-7cm long often in pairs.
Seeds have tufts of hair, aiding in wind dispersal. It also spreads vegetatively and via human-mediated dispersal such as mowing, soil movement, contaminated machinery, and deliberate plantings.
Habitats include grasslands, shrublands, forests, pasture, rocky outcrops, riparian areas, gardens and roadsides.
What you need to know
Overtakes and suppresses other vegetation, reducing species diversity and wildlife habitat, particularly in open areas as well as displacing pasture.
Infestations can eventually cover several acres of land and the tangled vines form impenetrable thickets.
Black swallow-wort is very tolerant and can easily spread in vulnerable habitats such as rocky outcrops and riverbeds.
Management approach
Black swallow-wort is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.
These species pose a high risk to our environment, economy, recreation, and cultural values.
Control
Do not attempt to undertake control of black swallow-wort yourself.
Report any sightings to us, we will confirm identification and undertake control.
The leaves are dark green, tapered at the end and between 5-12cm in length
Flowers are star-shaped, dark purple and are visible from late spring to late summer
Fruits/pods are slender and smooth, between 5-7cm long often in pairs
Habitats include grasslands, shrubland, forest, pasture, rocky outcrops, riparian areas, gardens and roadsides
