Salicaceae: Willow Family — Willows & Cottonwood
All members of this family are dioecious, with male and female flowers borne on separate trees. All produce catkins, the male catkins appearing yellow or red depending on the color of the pollen and female catkins appearing green until they ripen and release of fine, cottony seeds. Distinguishing the willows can be tricky. The shape of the leaf is generally critical, whether the leaves appear before, at the same time as or after the catkins can be indicative and, in some cases the number of stamens in each individual flower in the male catkin, something that can be seen with a hand lens but hard to see with the naked eye.