Plant DetailShow Menu

Inula helenium

Common Name(s):

Phonetic Spelling
IN-yoo-luh hel-EH-nee-um
Description

Inula, in the Asteraceae (daisy) family, is a very recent introduction to North America. A native of Europe, this perennial weed has been introduced to several nurseries in contaminated hostas and daylilies from the Netherlands. Once introduced, the plant spreads aggressively by thick, fleshy roots that produce new shoots. Plants form rosettes of long, thin leaves that resemble some asters or fleabanes. The leaves also resemble buckhorn plantain leaves except plantain leaves have five distinct parallel veins; Inula leaves have netted veins. Leaves are 3 to 10 inches long and about 1/2 to 1 inch wide. Leaves remain green through the winter. Plants require a chilling period to flower. In the spring plants spread rapidly, then in early to mid-summer flowering stems begin to elongate. Plants produce attractive, typical aster-like flowers, yellow to light orange in color. It is unclear whether or not the species produces viable seeds in North America. Because the plant primarily reproduces vegetatively, preemergence herbicides commonly used are not effective. It is nearly impossible to remove all of the Inula root pieces; consequently, if a container plant is infested with Inula it should be destroyed before the weed can spread.

Cultivars / Varieties:
Tags:
#invasive#biennial#perennial#weed#yellow flowers#aggressive#spreading#Noxious Weed List
 
Cultivars / Varieties:
Tags:
#invasive#biennial#perennial#weed#yellow flowers#aggressive#spreading#Noxious Weed List
  • Attributes:
    Genus:
    Inula
    Species:
    helenium
    Life Cycle:
    Biennial
    Perennial
    Country Or Region Of Origin:
    Europe
  • Whole Plant Traits:
    Plant Type:
    Wildflower
    Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Coarse
  • Flowers:
    Flower Color:
    Gold/Yellow
    Flower Inflorescence:
    Cyme
    Head
    Flower Bloom Time:
    Fall
    Summer
    Flower Petals:
    more than 20 petals/rays
    Flower Size:
    3-6 inches
    Flower Description:
    Narrow, string-like yellow petals
  • Leaves:
    Leaf Characteristics:
    Deciduous
    Leaf Color:
    Green
    Leaf Feel:
    Velvety
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Lanceolate
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Description:
    Large, rough alternate leaves with a woolly underside.; finely toothed, basal leaves are 10-12 in. long; narrows at the base into long stalks; upper leaves are smaller, stalkless and often clasp the stem by heart-sjhaped base; densley woolly stems
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
    Stem Form:
    Straight
    Stem Leaf Scar Shape:
    Heart or shield shaped
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    Densley woolly