bitterweed

• 名词，指几种杂草，包括一种常见的欧洲杂草，具带刺的舌状叶和黄色花，已归化于美国；也指多种北美豚草属植物，其花粉高度致敏，可引发花粉症和哮喘。

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.

   苦草

   • 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.

   同义词oxtongue

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.

   豚草

   • 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.

   同义词ambrosiaragweed