bitterweed

Definitions of bitterweed

1. noun

   widespread European weed with spiny tongue-shaped leaves and yellow flowers; naturalized in United States
   synonyms: Picris echioides, bristly oxtongue, bugloss, oxtongue

   type of:

   weed

   any plant that crowds out cultivated plants
2. noun

   any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma
   synonyms: ambrosia, ragweed

   types:

   Ambrosia artemisiifolia, common ragweed

   annual weed with finely divided foliage and spikes of green flowers; common in North America; introduced elsewhere accidentally

   Ambrosia trifida, great ragweed

   a coarse annual with some leaves deeply and palmately three-cleft or five-cleft

   Ambrosia psilostachya, perennial ragweed, western ragweed

   coarse perennial ragweed with creeping roots of dry barren lands of southwestern United States and Mexico

   type of:

   weed

   any plant that crowds out cultivated plants