bitterweed

• Nom désignant plusieurs plantes adventices, notamment une mauvaise herbe européenne commune à feuilles lancéolées épineuses et à fleurs jaunes, naturalisée aux États-Unis, ou diverses plantes nord-américaines du genre Ambrosia (ambroisie) dont le pollen très allergène provoque rhume des foins et asthme.

A noun referring to any of several weedy plants, including a widespread European weed with spiny tongue-shaped leaves and yellow flowers naturalized in the United States, or various North American plants of the genus Ambrosia that produce highly allergenic pollen causing hay fever and asthma.

1. B2formalscientific

   A widespread European weed with spiny tongue-shaped leaves and yellow flowers, naturalized in the United States.

   herbe amère (Picris hieracioides)

   • Bitterweed can be found in many fields across the Midwest.
   • The yellow flowers of bitterweed bloom in late summer.
   • Farmers often try to control bitterweed because it spreads quickly.

   Synonymesoxtongue

2. RagweedB2formalamericanscientific

   Any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma.

   Ambroisie

   • Bitterweed pollen is a major cause of seasonal allergies.
   • Many people suffer from hay fever due to bitterweed in late summer.
   • Bitterweed plants release large amounts of pollen into the air.

   Synonymesambrosiaragweed