The Ohio State University at Marion

Invasive Species


Blooms June - September

The deep bluish purple flowers of Bottle Gentian never fully open, giving them their characteristic bottle-like appearance. Its shape prevents all but the largest insects from entering. Bumblebees force themselves inside by pushing the petals apart. One of the last plants to bloom in fall, it grows one-to-two feet tall.

Canada Thistle

Blooms June - August

Common Milkweed grows two-to-four feet tall and produces a profusion of sweet-scented mauve flowers clustered together in domed groups in mid-summer. Monarch caterpillars feast on the leaves, become butterflies and migrate to Mexico for the winter. The caterpillars ingest the toxic sap of the milkweed plants with no ill effects. The Monarch butterflies then have a toxic defense against predators like birds. The seed pods of Common Milkweed are gray and warty but when they break open they reveal seeds attached to silky fluffs which help carry the seeds on the wind.


Lanceleaf Coreopsis

Michigan Lily

Ohio Spiderwort

Ox-Eyed Sunflower

Rattlesnake Master

Smooth Petunia

Smooth Rose

Sullivant's Milkweed



Thin Leaved Coneflower

Wing Angled Loosestrife