When people think of signature species of the National Parks, grizzlies and bison come immediately to mind. But an exhibit at the U.S. Botanic Garden celebrating the 100th anniversary of the National Park Service focuses on the lesser-known signature species—flora rather than fauna.

“Flora of the National Parks”—a mix of botanical drawings, paintings, and photographs—features some of the plants one may expect, including Joshua trees and the Rocky Mountain columbine, the latter in a glorious shade of blue. But it’s also a day in the sun for such humble species as the red osier dogwood, the mountain lady’s slipper, and the pond apple.

Some of the portrayals are unexpectedly bold—Hilary Grabowska’s jack-in-the-pulpit made from cut paper, a bald cypress swamp with ghost orchids painted by Mary Ruden in the style of Henri Rousseau, and a pair of watercolors by Stephanie Ryan that seems far too colorful to depict parks in Alaska.

Simpler, though, is often better. Various artists hit the right note with their scientifically minded renderings of pine cones from Redwood, Sequoia, Crater Lake, and Lassen Volcanic parks. And Thomas Arledge steals the show with his photograph of a thick forest of white-barked aspens—an elegant depiction of one of the parks’ most elegant species.

Through Oct. 2 at the U.S. Botanic Garden, 100 Maryland Ave. SE. 10 a.m.-5 p.m. daily.