Are many lupine plants in Maine considered invasive species?

The vast majority of lupine plants seen in Maine — known for their tall spikes of bright purple flowers — aren’t native to the state and are considered invasive by many botanists.

The bigleaf lupine (Lupinus polyphyllus), also called western lupine, is native to the West Coast and is listed on Maine’s invasive plant advisory list as “potentially invasive” by the state Department of Agriculture, Conservation and Forestry.

Maine’s only native lupine species, the sundial lupine (Lupinus perennis), once supported native pollinators such as the endangered Karner blue butterfly, but it is now believed to be largely extirpated — a term meaning locally extinct — in the wild. The bigleaf lupine has primarily taken its place.

Coastal Maine Botanical Gardens recommends that Mainers remove bigleaf lupines from their gardens and replace them with sundial lupines, which can still be purchased from many nurseries and online seed sellers, despite being locally extinct in the wild.