Deep water aquatic plants are those which grow on the bottom of the pond or on the deeper shelves, so that they have several inches of water over their crown. Their foliage and flowers either float on the surface like those of a waterlily, or emerge from the water. Unlike other marginal plants, deep water aquatic plants can't be grown out of the water in places such as damp flowerbeds - they do require at least some water over their crown. Those with upright stems offer important places for insects such as dragonflies to emerge, while those with floating leaves provide cover and shade for the pond. The deep water aquatics with floating leaves, such as Water Hawthorn or Floating Heart, can be a useful alternative if your pond is not large enough or sunny enough for waterlilies. They also tend to give the pond a more informal look than waterlilies do.