Inula

Inula helenium

Inula

Family: Asteraceae

Other Common Names: elecampane, yellowhead
Weed class: monitor list
Native to: Asia and Europe
Is this Weed Toxic?:

potential allergic reactions

Why Is It a Noxious Weed?

This plant is on the monitor list. Please contact its sponsor Sue Winterowd to report locations or for more information.

How would I identify it?

General Description

Large, perennial herbaceous plant, growing sometimes as tall as 6+ feet, with a thick branching root. Stems and leaves are hairy.

Flower Description

Plants have few flowerheads, occuring on stems (peduncles). Flowerheads are 2.4-3.5 inches (6-9 cm) wide. Ray flowers are slender and yellow (rarely white) and disk flowers are yellow. Typically flowerheads have more than 50 ray flowers, mostly 0.6-1 inch (1.5-2.5 cm) long. The involucre (bracts subtending the flowers) about 0.78-1 inch (2-2.5 cm) high.

Leaf description

Leaves large, growing up to 19.7 inches (50 cm) long and 7.8 inches (20 cm) wide. Lower leaves have long petioles and are elliptic while upper leaves become sessile and clasping and are ovate (egg-shaped) to cordate (heart-shaped). Leaf margins are irregularily toothed, sparsely spreading-hairy to glabrous above and densely velvety hairy below.

Fruit Seed Description

Seed slender, about 4-angled, hairless with typically a reddish pappus.

Where does it grow?

Introduced as a garden ornamental, inula has naturalized in the NE U.S. and along the west coast. One site of escaped and spreading plants was found in Stevens County in the 1990's on an old homestead site. Plants grow in moist areas, full sun to part-shade, and is found along roadsides, fields, pastures, open woodlands and other disturbed sites.

How Does it Reproduce?

It spreads by seed and has been noted to spread vegetatively.

For More Information

U.S. Forest Service Weed of the Week

Additional Photos