| The Araceae of temperate North America (Canada and the continental United States) are reviewed, resolving problems involving their systematics, natural history, and ethnobotany. The aroid genus Peltandra and North American Acoraceae are revised.;A comprehensive review of North American Araceae is based on direct examination of over 180 populations in the field, and study of almost 12,000 herbarium specimens. Seven aroid genera with a total of nine species are native to temperate North America plus species in ten introduced genera have been documented outside of cultivation. A key to all species is provided, and each species is discussed with illustrated sections on morphology, synonymy, taxonomy, habitat, distribution (mapped), reproductive phenology, conservation status, ethnobotany, distinguishing features, biology, and specimens examined.;A comprehensive revision of Peltandra, one of only two aroid genera endemic to temperate North America, is presented, recognizing two extant species (P. sagittifolia (Michaux) Morong and P. virginica (Linnaeus) Schott) and one fossil species (P. complicatum (Lesquereux) S.A. Thompson, new combination). Although recent authors have treated Peltandra as consisting of a single species with two subspecies, this study quantitatively characterizes two distinct extant species, P. sagittifolia and P. virginica, based on characters of the inflorescence, infructescence, and leaf venation. New information on the biology of Peltandra is presented, including controlled pollination experiments involving P. virginica. Pollination is accomplished by adults of a chloropid fly, Elachiptera formosa, which use inflorescences as sites for mating, oviposition, and larval development.;Traditional circumscription of the Araceae included the aberrant genus Acorus, placed by recent authors in its own family, the Acoraceae. A revision of the Acoraceae of North America is presented, resolving problems involving the number of species in this region, native status, and correct nomenclature for American taxa. Studies of morphology, pollen stainability, isozymes, nomenclature, and use by Native Americans are consistent with recognition of two species of Acorus in North America, A. calamus Linnaeus, a sterile triploid introduced by European settlers, and A. americanus (Rafinesque) Rafinesque, a native fertile diploid species. Data on essential oil chemistry, phytopathology, and karyology support that conclusion. |
