Acalypha

thumb|right|Acalypha capitata thumb|Firetail Chenille Plant, Acalypha pendula thumb|right|Acalypha fruticosa thumb|right|Acalypha cuneata thumb|right|Acalypha indica Acalypha is a genus of flowering plants in the family Euphorbiaceae. It is the sole genus of the subtribe Acalyphinae. It is one of the largest euphorb genera, with approximately 450 to 462 species. The genus name Acalypha is from the Ancient Greek () ("nettle"), an alternative form of (), and was inspired by the nettle-like leaves. General common names include copperleaf and three-seeded mercury. Native North American species are generally inconspicuous most of the year until the fall when their stems and foliage turn a distinctive coppery-red.

The genus is distributed mainly in the tropics and subtropics, with about 60% of species native to the Americas and about 30% in Africa.