: Flowers are typically unisexual and highly simplified, often lacking petals or having insignificant sepals.
: Male flowers (and sometimes female) are borne in catkins —tassel-like, often pendulous spikes of reduced flowers.
: Fossil evidence indicates that recognizable members of this group emerged primarily in the Late Cretaceous period. Paleobotanical Significance Fossil forms of Amentiferae | Brittonia - Springer Nature amentiferae
Members were grouped together based on a specific suite of reproductive features suited for wind pollination ():
: The group is "artificial" because catkin-bearing evolved convergently. For instance, Salicaceae is now known to be unrelated to the "core" amentiferous plants and is placed in the order Malpighiales. : Flowers are typically unisexual and highly simplified,
(or Amentaceae) is a historically significant but now largely obsolete botanical group of woody plants characterized by bearing catkins (aments). While once considered a natural evolutionary group, modern molecular phylogenetics has revealed it to be an artificial collection of unrelated families that independently evolved similar wind-pollination traits. Historical Classification and "Canonical" Families
The term was most influential in the 19th and early 20th centuries, particularly under the systems of botanists like Eichler. It typically included: : Birches and alders. Fagaceae : Oaks, beeches, and chestnuts. Juglandaceae : Walnuts and hickories. Salicaceae : Willows and poplars. Casuarinaceae : Beefwoods or she-oaks. Myricaceae : Bog myrtles. Key Biological Characteristics While once considered a natural evolutionary group, modern
: Most former Amentiferae (oaks, birches, walnuts) are now placed in the order Fagales , which is part of the Rosid I clade.