(Amentiferae) A subclass of the dicotyledons containing mainly woody plants often with small unisexual apetalous flowers frequently borne in catkins. The number of orders recognized varies between about seven and fifteen. The Trochodendrales; the Hamamelidales, including the Platanaceae (e.g. plane trees) and Hamamelidaceae (e.g. witch hazels); the Eucommiales; the Leitneriales; the Myricales, including the Myricaceae (e.g. sweet gale); the Fagales, including the *Fagaceae
(e.g. beeches, oaks, and chestnuts); and the Casuarinales, including the Casuarinaceae (e.g. she oaks) are usually recognized. Additional orders include the Cercidiphyllales and Eupteleales (both often included in the Trochodendrales); the Urticales (often included in the subclass *Dilleniidae
); the Betulales, including the Betulaceae (e.g. alders, birches, hazels, and hornbeams), and the Balanopales (both often placed with the Fagales); the Juglandales (often included in the subclass Rosidae); and the Didymelales and Barbeyales.