n.

widespread European weed having yellow daisylike flowers; sometimes an obnoxious weed and toxic to cattle if consumed in quantity

同義詞：ragworttansy ragwortbenweedSenecio jacobaea

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

同義詞：ambrosiabitterweed

Ragweeds (Ambrosia L.) in Britain
Ragweeds (Ambrosia spp.): The Hay Fever Weeds
RAGWEEDS, AMBROSIA SPECIES, IN CANADA AND THEIR HISTORY IN POSTGLACIAL TIME
The North American ragweeds and their occurrence in other parts of the world.
THE MORPHOLOGY OF THE INFLORESCENCE OF RAGWEEDS (AMBROSIA〧RANSERIA : COMPOSITAE)
Ecological characteristics of the ragweeds and countemeasure of the biological weed control
FLOWERING BEHAVIOR AND NATURAL DISTRIBUTION OF THE EASTERN RAGWEEDS (AMBROSIA) AS AFFECTED BY LENGTH OF DAY
The Phytophagous Insect Faunas of the Ragweeds, Ambrosia chenopodiifolia, A. eriocentra , and A. ilicifolia , in Southern California
[Biological and clinical prevalence of pollinosis caused by ragweeds of the upper valley of the Rhone corridor]
Pollen-wall proteins: Localization of antigenic and allergenic proteins in the pollen grain walls of Ambrosia spp. (ragweeds)