The Collaborative International Dictionary
Malvaceous \Mal*va"ceous\, a. [L. malvaceus, from malva mallows. See Mallow.] (Bot.) Pertaining to, or resembling, a natural family of plants ( Malvace[ae]), of which the mallow is the type. The cotton plant, hollyhock, and abutilon are of this family. It was formerly classified as an order, and included the baobab and the silk-cotton trees. The baobab and silk-cotton trees are now placed in the family Bombacaceae, which is included with the Malvaceae in the order Malvales.
Wiktionary
a. Of or pertaining to plants in the mallow family, http://en.wikipedia.org/wiki/Malvaceae.
Usage examples of "malvaceous".
He refers to the 'Paritium tiliaceum', a malvaceous plant, hardly noticed by Europeans, but very highly prized by the natives of the tropics, and cultivated everywhere in the East and West Indies.