COMOSAE, in botany, from Coma. An order of plants in the former editions of Linnaeus's Fragments of a Natural Method, consisting of the spiked willow or spirea frutex, dropwort, and greater meadow-sweet. These, though formerly distinct genera, are by Linnaeus collected into one, under the name of spirea. The flowers growing in a head, resemble a bush, or tuft of hair, which probably gave rise to the epithet Comosa.