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Marestail (Conyza canadensis)

Marestail (Conyza canadensis)

Description: An annual plant reaching 1'-6' in height. Mature plants have a single erect stem terminating in a horse-tail like, much branched flower cluster. 

Life cycle: Winter or summer annual.

Habitat: Crop Fields, pastures, orchards, fallow fields, roadsides and waste areas.

Leaf: Young plants appear as a circle of leaves before stem elongation. Young leaves may be up to 4" long, alternately arranged, and crowded along stem. Leaves become progressively smaller up the stem. 

Stem: Single, unbranched stem, Solid and bristly hairy, reaching 6.5' in height.  Dead "skeleton" stems can persist along roadsides or in fields throuhgout the dormant season.  

Flower: A much-branched flower cluster is produced at the top of the central stem. Individual flowers are 5 mm in diameter and inconspicuous.

Root: Short taproot with a secondary fibrous root system.

The problem is….marestail is competitive, can interfere with harvest, reduce crop yield and may be resistant to multiple classes of herbicides.  A very problematic weed in crop production. 

marestail sapling

Marestail field, 7133.

Marestail field

Marestail close-up, 5967.

Marestail flower, Wendy VanDyk Evans, Bugwood.org.

Marestail turning brown, 10130.