Eschara or hornwrack, a species of coralline, resembling woven cloth in texture, consisting of arrangements of very small cells. One species is called narrow-leaved hornwrack; another, the broad-leaved hornwrack. This name is given also to the keratophyta, horn-plant, or sea-shrub, a species of Gorgonia.

Having the form of coral; branching like coral.