A prolific science writer takes on bark, roots, pollen, and the other parts of trees, all depicted in striking color photos; the color-enhanced, carefully labeled microscopic photos (showing the inside of a seed, stoma, sapwood tubes, and more) are especially fascinating. Markle's text is thoughtful and vivid- -``Imagine what it would be like if you only grew taller from the top of your head and the tips of your toes.'' The cycle of seasons- -new buds, green leaves, fall colors, bud scars—is also covered; a tree's growth from seed to maturity is detailed in the excellent photos. An attractive book that effectively conveys a sense of wonder. Pronunciation guide; glossary/index. (Nonfiction. 5-10)