Canadian Horseweed

Conyza canadensis (L.) Cronquist - Aster family

Size

Mature Height: Up to around 6.0 feet

Plant Type: Forb/herb

Features

Flower Color: White, Yellow, Purple

Conspicuous Flowers: Yes

Bloom Time: Winter, Early Spring, Mid Spring, Late Spring, Early Summer, Mid Summer, Late Summer, Fall

Conditions

Shade Tolerance: Intolerant

Ecosystem Interactions

Pollinators: Native Bees; Beetles, Wasps, Flies; Larval Host (Butterfly); Larval Host (Moth)

Larval Species depending on Canadian Horseweed: Charidryas nycteis, Chlorochlamys chloroleucaria, Ctenoplusia oxygramma, Cucullia florea, Cucullia speyeri, Eupithecia miserulata, Peridroma saucia, Sparganothis sulfureana, Spodoptera ornithogalli, Synchlora aerata, Synchlora aerata aerata

Native Range

  • USA:  Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode I., South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming
  • CAN:  Alberta, British Columbia, Manitoba, Nova Scotia, Ontario, Prince Edward I., Québec, Saskatchewan
  • MEX:  Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest
  • USA+:  Puerto Rico
Regional Native Status: L48 (N), AK (I), HI (I), PR (N), VI (N), CAN (N), SPM (N)

State-level native status is based on data available through Plants of the World Online. Regional Native Status comes from the USDA Plants Database. For more detailed native status information, please refer to BONAP.