On the cover: This photo of Engelmann’s hedgehog cactus (Echinocereus engelmannii) was taken in 2013 at Coconino National Forest, near Flagstaff, New Mexico. The flowers of this cactus are bright and colorful and are followed by spiny, greenish fruits that turn red when they ripen. Photo taken by William Dahl, Executive Director of the Botanical Society of America (www.botany.org). More of his photos can be found at www.great-story.net.