Ageratum (/əˈdʒɛrətəm/)[2] (whiteweed in the US) is a genus of 40[3] to 60 tropical and warm temperate flowering annuals and perennials from the family Asteraceae, tribe Eupatorieae.

[citation needed] The fluffy flowers are lavender-blue, pink, lilac, or white, and spread in small compound umbels.

Most common ageratums, "Hawaii" for example, are a short 6–8 inches (15–20 cm) when full grown.

[4][failed verification] There is also a medium-height snowcapped variety, white top on blue flowers.

Their size and color makes ageratums good candidates for rock gardens, bedding, and containers.