Catkins

Catkins, also called aments, are slim, cylindrical inflorescences found on many deciduous trees and shrubs, especially wind-pollinated genera such as Salix (willows), Populus (poplars and aspens), Betula (birches), Alnus (alders), and Corylus (hazel). They typically appear in late winter or early spring, often before leaves emerge. Catkins may be male or female; many species are monoecious with separate male and female catkins on the same plant, while others are dioecious with one sex on different plants.

Each catkin is composed of numerous small flowers densely arranged on a central stalk. Male catkins bear inconspicuous flowers with anthers that shed pollen, while female catkins carry flowers with ovules and stigmas. Because catkins lack showy petals, they rely on wind to carry pollen, which makes them a common sight in early spring as trees shed pollen.

After pollination, female catkins enlarge into seed-bearing structures. In many species the seeds are designed for wind dispersal and may be released when mature. Catkins are often short-lived, especially the male ones, and their appearance can be a useful identifier for certain tree species in temperate regions.

Ecologically, catkins provide an important early source of pollen for bees and other insects in spring. They are a characteristic feature of several tree groups and can help distinguish species in winter and early spring landscapes.