Malvaceous Mal*va"ceous, a. [L. malvaceus, from malva mallows. See Mallow.] (Bot.) Pertaining to, or resembling, a natural order of plants (Malvace[ae]), of which the mallow is the type. The cotton plant, hollyhock, and abutilon are of this order, and the baobab and the silk-cotton trees are now referred to it.