Treehugger/ Alexandra Cristina Nakamura. Besides its branches, roots, and leaves, a mature tree also grows another important structure—the flower (or cone, in the case of evergreens).

The pin oak’s pyramidal shape and fine branches provide a year-round silhouette in the backyard. The glossy green leaves turn ...

A leafless Garry oak silhouette would work well as the spooky background of a horror movie or Halloween flick, accented by flashes of lightning. “In the winter, they look kind of scary,” said ...