ageratum

名词 ageratum:

1. rhizomatous plant of central and southeastern United States and West Indies having large showy heads of clear blue flowers; sometimes placed in genus Eupatorium
   同义词：mistflower, mist-flower, Conoclinium coelestinum, Eupatorium coelestinum
2. any plant of the genus Ageratum having opposite leaves and small heads of blue or white flowers