Galinsoga quadriradiata Cav.
Galinsoga aristulata E.P. Bicknell
Galinsoga bicolorata H. St. John & D. White
Galinsoga caracasana (DC.) Sch. Bip.
Galinsoga ciliata (Raf.) S.F. Blake
Hairy Galinsoga, Shaggy Soldier
Hairy galinsoga is a widespread weed that is easily overlooked, with small flowers and few distinctive features, unless you are a farmer and it is ruining your crop yields. These inconspicuous weeds can reduce crop yields by 50%. They are believed to have originated in Mexico.
Identification: Plants are 4-31" (10-80 cm) high, often branched; stems are covered with short hairs. Leaves are opposite, medium to dark green, and up to 2" (6 cm) × 1½" (4 cm). They are broadest at the base, tapering to a tip, sparsely to densely hairy, and coarsely toothed. Flowers are ¼-⅜" (6.3-10 mm) in diameter, with 4 or 5 petals, each with three teeth; and a central yellow disk. Fruits are small achenes with little plumes.
Galinsoga quadriradiata on Discover Life
Galinsoga quadriradiata at Illinois Wildflowers
Galinsoga quadriradiata at the University of Wisconsin's Robert W. Freckmann Herbarium
Galinsoga quadriradiata on www.gri.msstate.edu
Galinsoga quadriradiata on the USDA Plants Database
Galinsoga quadriradiata at Minnesota Wildflowers
Galinsoga quadriradiata on eFloras
Galinsoga quadriradiata description by Thomas H. Kent, last updated 15 Oct 2013.