Catkin

Catkin is a tassellike flower cluster that consists of numerous small flowers arranged around a long central axis. Each flower lacks the colored petals that are typical of most familiar wildflowers. For this reason, the grayish- or yellowish-green catkins are rarely thought of as flowers. Each catkin is either staminate (male, producing pollen) or pistillate (female, producing seeds). The wind pollinates the female catkins. The most familiar catkin is the pussy willow. Catkins appear on the branches of willows, alders, and poplars long before other spring flowers appear. Most catkins are long and drooping. They are also called aments.

River birch catkins
River birch catkins