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Ohio State University Extension


Marestail (Conyza canadensis)

Marestail (Conyza canadensis)

Description: An annual plant reaching 1'-6' in height. Mature plants have an erect central stem with leaves that are entirely without petioles and inconspicous clustered flowers at the top.

Life cycle: Winter or summer annual

Habitat: Agronomic crops, pastures, orchards, fallow fields, waste areas and roadsides.

Leaf: Mature plants have leaves that are entirely without petioles. Leaves are 4" long, alternately arranged, and crowded along stem. Leaves become progressively smaller up the stem.

Stem: Solid and bristly hairy, reaching 6.5' in height.

Flower: Many inconspicuous flower heads occur at the top of the central stem. Individual flowers are 5 mm in diameter with white or slightly pink ray flowers and yellow disk flowers.

Root: Short taproot with a secondary fibrous root system.

The problem is….marestail is competitive, can interfere with harvest, reduce crop yield and is somewhat resistant to herbicides.

marestail sapling

Marestail field, 7133.

Marestail field

Marestail close-up, 5967.

Marestail flower, Wendy VanDyk Evans,

Marestail turning brown, 10130.