Invasive Plants of Wisconsin
|Inula helenium L.
Inula helenium is a tall herbaceous perennial plant, up to 1.5 - 2 meters tall with alternate, simple leaves. Lower leaves are tapered to the base or even petioled and the upper stem leaves are usually clasping the stem. The leaf blades are large and coarse, up to 50 cm long and 20 cm wide, with entire margins, rough on the upper surface and usually wooly beneath. Young plants will produce only basal leaves and will not flower for 1 to several years before sending up the tall flowering stem. In well established populations there are typically both flowering and immature plants together.
This species was introduced from Europe and has become naturalized in northeastern United States and also along the western coast. Its distribution in Wisconsin is undoubtedly more widespread than the map indicates, perhaps because the very large size of the plant discourages the taking of vouchers to document its presence. It is not yet listed as an invasive plant in Wisconsin, but in some circumstances it can be very aggressive.