ragweeds

'ragweeds'

[ragwort.n.01] as in: widespread European weed having yellow daisylike flowers; sometimes an obnoxious weed and toxic to cattle if consumed in quantity

'ragweeds'

[ragweed.n.02] as in: any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma