marshmallow the name of both a plant and a confection. The former, Althaea officinalis, a common plant of Europe and Asia, is related to the common mallow but looks more like the hollyhock. Although its leaves are edible, the chief use of the plant lies in its roots, which yield a mucilaginous substance which is the traditional basis for the sweet confections known as marshmallow but has now been almost entirely replaced by gum arabic.

The sweet confection is made from syrup cooked to the hard ball stage (see sugar boiling), then combined with a gelatin or gum arabic solution, often with colouring and flavouring (mint, strawberry, orange flower water, etc.), and whisked into beaten egg whites. The mixture, dusted with icing sugar, is left to set, then cut into cubes or rounds.