190. Alismataceae Ventenat
Water-plantain or Arrowhead Family
Robert R. Haynes ;C. Barre Hellquist
Herbs, annual or perennial, rhizomatous, stoloniferous, or cormose, caulescent, glabrous to stellate-pubescent; sap milky. Roots septate or not septate. Leaves basal, submersed, floating, or emersed, sessile or petiolate, sheathing proximally; blade with translucent markings of dots or lines present or absent, basal lobes present or absent; venation reticulate, primary veins parallel from base of blade to apex, secondary veins reticulate. Inflorescences scapose racemes or panicles, rarely umbels, erect, rarely floating or decumbent, whorled (forming racemes) or whorls branching (forming panicles), bracteolate. Flowers bisexual or unisexual, if unisexual, staminate and pistillate on same or different plants, hypogynous, subsessile to long-pedicellate; sepals persistent, 3; petals deciduous, 3, delicate; stamens 0, 6, 9, or to 30, distinct; anthers 2-loculed, dehiscing longitudinally; pistils 0 or 6--1500 or more, distinct or coherent proximally, 1-loculed; placentation basal; ovules1--2. Fruits achenes or follicles. Seeds: embryo U-shaped; endosperm absent in mature seed.
Genera 12, species ca. 80 (4 genera, 34 species in the flora): nearly worldwide, primarily tropical and subtropical regions.
SELECTED REFERENCES
Argue, C. L. 1974. Pollen studies in the Alismataceae (Alismaceae). Bot. Gaz. 135: 338--344. Argue, C. L. 1976. Pollen studies in the Alismataceae with special reference to taxonomy. Pollen & Spores 18: 161--173. Beal, E. O. 1960b. The Alismataceae of the Carolinas. J. Elisha Mitchell Sci. Soc. 76: 68--79. Charlton, W. A. 1973. Studies in the Alismataceae. II. Inflorescences of Alismataceae. Canad. J. Bot. 51: 775--789. Correll, D. S. and H. B. Correll. 1972. Aquatic and Wetland Plants of Southwestern United States. Washington. Godfrey, R. K. and J. W. Wooten. 1979. Aquatic and Wetland Plants of Southeastern United States: Monocotyledons. Athens, Ga. Haynes, R. R. and L. B. Holm-Nielsen. 1985. A generic treatment of Alismatidae in the Neotropics. Acta Amazôn. 15(suppl.): 153--193. Haynes, R. R. and L. B. Holm-Nielsen. 1994. The Alismataceae. In: Organization for Flora Neotropica. 1968+. Flora Neotropica. 75+ nos. New York. No. 64, pp. 1--112. Rogers, G. K. 1983. The genera of Alismataceae in the southeastern United States. J. Arnold Arbor. 64: 387--424.
