"of or pertaining to the mallow," 1690s, from Late Latin malvaceus, from Latin malva (see mallow).
Entries linking to malvaceous
mallow n.
late 14c., spelling alteration of late Old English malwe and directly from Latin malva "mallows" (source also of Modern French mauve, Spanish and Italian malva), a word from a Mediterranean substrate language. The same lost word apparently yielded Greek malakhe "mallow."