University of Missouri Extension

IPM1007, Revised November 2009

Practical Weed Science for the Field Scout: Corn and Soybean

Horseweed or Marestail (Conyza canadensis)

Summer annual broadleaf

HorseweedHorseweed
 

HorseweedAn erect winter or summer annual that may reach as much as 6-1/2 feet in height. Seedlings have cotyledons that are small and oval, first true leaves are egg shaped with toothed margins, becoming hairy with age. Mature plants have leaves that are entirely without petioles, hairy, alternate, linear and usually toothed. Leaves become progressively smaller up the stem. Small white flower heads occur at the top of the central stem. Many small white bristles are attached to the achene, which facilitates aerial dispersal of the seed.

HorseweedHorseweed
 

IPM1007, revised November 2009

Wild thing
 

IPM1007 Practical Weed Science for the Field Scout: Corn and Soybean | University of Missouri Extension

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