Dictionary.net

• common North American weed with linear leaves and small discoid heads of yellowish flowers; widely naturalized throughout temperate regions; sometimes placed in genus Erigeron

2006 - WordNet 3.0
By Princeton University

• common North American weed with linear leaves and small discoid heads of yellowish flowers; widely naturalized throughout temperate regions; sometimes placed in genus Erigeron

2011 - English Dictionary Database
By DataStellar Co., Ltd