As seen in numerous (mostly USDA) photographs, water plants are a varied group whose special features and adaptations are systematically reviewed here. Free-floating or rooted, flowering or non-flowering, salt-water or fresh living, they may be as small as algae, as large and imposing as cattails, or as peculiar as nullipores--solidified algae which look like an arrangement of flat pebbles. Hogner specifies size, shape, color, and preferred habitat, and indicates unusual characteristics--hyacinths often clog waterways, turtle grass is pollinated underwater. A final chapter suggests projects and experiments which those with access to a microscope and aquarium can most enjoy. A satisfactory introduction.