Flora of North America brings together for the first time ever in a concise and easy to understand format information on all the plants growing spontaneously in North America north of Mexico. Volume 22 is the first of five volumes covering monocots in North America north of Mexico. The volume comprises many groups of aquatic plants and the North American relatives of groups that have their richest number of species in the New World tropics. Included among the treatments are the rush family (Juncaceae), which include important indicator species in wetland habitats, the cat-tails (Typhaceae), spiderworts (Commelinaceae), aroids (Araceae), and pondweeds (eel-grasses) to stately Arecaceae (palms) and the naturalised exotic Zingiberaceae (gingers), Heliconiaceae (heliconias), and Musaceae (bananas). Identification keys, summaries of habitats and geographic ranges, distribution maps, pertinent synonymies, descriptions, chromosome numbers, phenological information, and other significant biological observations are given for each species. The treatments, written and reviewed by experts throughout the systematic botanical community, are based on original observations of herbarium specimens and, whenever possible, on living plants. These observations are supplemented by critical reviews of the literature.