Invasive Plants - Illustrated

Cape ivy (Senecio mikanoides) is an extremely invasive recent arrival from South Africa. It smothers all other vegetation, and may be toxic to aquatic life. Look for bright green, hairless leaves shaped like ivy but more delicate, with a pungent smell; some bright pink stems; and yellow flowers in winter.

Perennial pepperweed (Lepidium latifolium) is a major threat to local wetlands, especially salt marshes. The first picture shows this invasive plant in bloom, note the many tiny white flowers on top of erect dark green stems. The second picture shows the young plants invading through creeping rhizomes.

Giant cane or Giant reed (Arundo donax) is an extremely invasive, tall, bamboo-like grass with the ability to take over streamsides by spreading through rhizomes under the soil surface.

Three non-native grasses that displace natives:

Ripgut brome, left, can be distinguished from native bromes by the long awn - the thread-like fiber projecting from the seed. In ripgut, the awn is much longer than the seed, 1/2" long or more. As the grass matures, the seeds will be more visible individually, many on each stalk.

Italian ryegrass, center, is a shiny-leaved grass whose seeds form a slight zig-zag outline on the sides of the thin, upright flower stalk.

Wild oats, right, is a tall grass with awns framing heavy, stout individual seeds.

Back to Invasive Plants

More Information Sheets

HOME - Calendar - Contacts