MY YARD IS FULL of eastern white pine trees, and every three years or so, it is full of pine cones. This is one of those years. Pine cones have fallen all over the yard, the sidewalk, the driveway.

Catkins and cones are the blooms of trees and shrubs whose flowers are sorted in a binary fashion—male and female. They are the quiet pleasure of those who notice botanical details, and they reward ...

Female (left) and male spruce cones at the Arnold Arboretum. It's a more common sight to see separate male and female cones like this. (Courtesy William "Ned" Friedman) Every spring the conifer trees ...