What is "hamamelidae"

Dicotyledonae \Dicotyledonae\ n. (Bot.) a class of plants comprising those seed plants that produce an embryo with two cotyledons and net-veined leaves; divided into six (not always well distinguished) subclasses (or superorders): Magnoliidae and Hamamelidae (considered primitive); Caryophyllidae (an early and distinctive offshoot); and three more or less advanced groups: Dilleniidae; Rosidae; Asteridae.

Syn: Dicotyledones, class Dicotyledones, class Dicotyledonae, Magnoliopsida, class Magnoliopsida.

Hamamelidae \Hamamelidae\ n. a group of chiefly woody plants considered among the most primitive of angiosperms; they have a perianth poorly developed or lacking, and flowers often unisexual and often in catkins and often wind pollinated. The group contains 23 families including the Betulaceae and Fagaceae (includes the Amentiferae); sometimes it is classified as a superorder.

Syn: subclass Hamamelidae.