Cotyledons
Rounded, thick
Short, broadly club-shaped

Roots
Fibrous

Stem
Erect, often hairy
Branched, bushy

True Leaves
Finely divided, fernlike,
Deeply lobed, lower leaves
opposite but become alternate

Flowers
Numerous, green
Clustered at branch tips

Habitat
Grain fields, waste areas,
roadsides, cultivated fields,
disturbed pastures

Note
Common cause of hayfever