Katherine (Kate) Olivia Sessions transformed the city of San Diego through her dedication to finding trees that could endure the climate and then planting them. Reading her story in The Tree Lady by H. Joseph Hopkins made me marvel at her determination and foresight. It is the illustrations, though, done by Jill McElmurry, that I adore. The gouache paintings invite a walk in the woods. Green hues prevail. Bark, twigs, leaves, needles, buds, veins, and soil come alive with textured detail. Tree species are carefully labeled and magnified on pages to emphasize Kate's thoughtful decisions of tree placement. Especially lovely are the envelopes she sent to gardeners like herself all over the world, asking for seeds. Kate lived from 1857-1940 and was awarded the Meyer Medal for her horticultural service in 1939.