Hamamelidae
       n : a group of chiefly woody plants considered among the most
           primitive of angiosperms; perianth poorly developed or
           lacking; flowers often unisexual and often in catkins and
           often wind pollinated; contains 23 families including the
           Betulaceae and Fagaceae (includes the Amentiferae);
           sometimes classified as a superorder [syn: subclass
           Hamamelidae]