Invasives

Invasive Plants

"Invasive" plants are non-native species that have spread into native or minimally managed plant systems in Massachusetts. These plants cause economic or environmental harm by developing self-sustaining populations and becoming dominant and/or disruptive to those systems.

Black swallow-wort

Black swallow-wort is a perennial vine that is native to Europe and can grow up to 8 feet long. It is a member of the milkweed family with dark green, glossy leaves, star-shaped purple flowers, and milkweed-like pods.

Japanese knotweed

This fall-blooming, herbaceous perennial can reach ten feet on hollow stems that resemble bamboo. Tolerant of difficult conditions, it forms large, dense colonies that are extremely difficult to control.

Roundleaf bittersweet

This twining woody vine is native to Japan, Korea, and China. Roundleaf bittersweet can grow to 60 feet, reaching the tops of mature trees, and strangling trees, shrubs, and other vines as it goes. In autumn, the yellow fruits split to reveal bright red seed coverings (arils).

Garlic mustard

Native to Europe, garlic mustard was first reported on Long Island in 1868, probably introduced via kitchen gardens. It is primarily a woodland plant and readily displaces all other understory growth.

Multiflora rose

Multiflora rose is a large perennial shrub that forms dense stands of impenetrable thickets that can grow to 30 ft in diameter by 6-10 ft tall, displacing native vegetation.