In this revised edition, Dr T.C. Brayshaw describes all of the aquatic monocotyledons in British Columbia. (Monocotyledons are a major subgroup of flowering plants that have embryos with only one seed leaf.) This group comprises four orders and fourteen families of plants in freshwater and marine environments. The most populous families are the pondweeds and bur-reeds, but others a re water-plantains, arrow-grasses, arums (Skunk Cabbage), duckweeds and cat-tails.