ragweed

名词 ragweed:

1. widespread European weed having yellow daisylike flowers; sometimes an obnoxious weed and toxic to cattle if consumed in quantity
   同义词：ragwort, tansy ragwort, benweed, Senecio jacobaea
2. any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma
   同义词：ambrosia, bitterweed

rag.weed

n.（名词）
Any of various weeds of the genusAmbrosia having small, greenish, unisexual flower heads and producing abundant pollen that is one of the chief causes of hay fever.
豚草：一种豚草 属的杂草，有绿色、单性花朵，能产大量花粉，是引起花粉热的主要原因之一
Chiefly British Ragwort.
【多用于英国】 千里光属

来源：
[From the ragged shape of its leaves]
[源于其叶片破裂的形状]