The arum family (Araceæ). Flowers in a fleshy spadix. Examples: Indian turnip (Arisæma), sweet-flag (Acorus), skunk-cabbage (Spathyema). The duckweed family (Lemnaceæ). (Examples: Lemna, Spirodela, Wolffia. See paragraphs 51-53.) =946. Order Xyridales=, from the genus Xyris, the yellow-eyed grass family (Xyridaceæ). Species mostly tropical, but a few in North America. Other examples are the pipewort family (Eriocaulaceæ, example, Eriocaulon septangulare), the pineapple family (Bromeliaceæ, example, the pineapple cultivated in Florida); the Florida moss or hanging moss (Tillandsia usneoides); the spiderwort family (Commelinaceæ), including the spiderwort (Tradescantia, several species in North America); the pickerel-weed family (Pontederiaceæ), including the genus Pontederia in borders of ponds and streams. =947. Order Liliales.=—Some of the families are as follows: The rush family (Juncaceæ, example, Juncus), with many species, plants of usually swamp habit. The lily family (Liliaceæ, examples: Lilium, Allium = Onion, Erythronium, Yucca). The iris family (Iridaceæ, examples: Iris, the blue-flag, fleur-de-lis, etc.). The lily-of-the-valley family (Convallariaceæ, examples: lily-of-the-valley, Trillium, etc.) The amaryllis family (Amaryllidaceæ, examples: Narcissus, the daffodil; Cooperia, in southwestern United States). =948. Order Scitaminales.=—This order includes the large showy cultivated Canna of the canna family. =949. Order Orchidales.= Example, the orchid family (Orchidaceæ) with Cypripedium, Orchis, etc. II. CLASS DICOTYLEDONES. SERIES 1. CHORIPETALÆ. Petals wanting (Apetalæ, or Archichlamydæ of some authors), or present and distinct from one another (Polypetalæ, or Metachlamydæ). =950. Order Casuarinales=, confined to tropical seacoasts (example, Casuarina). =951. Order Piperales= includes the lizard’s-tail family (Saururaceæ), Saururus cernuus, lizard’s-tail, in the eastern United States. =952. Order Salicales.=—Shrubs or trees, flowers in aments. Includes the willows and poplars (Salix and Populus of the willow family, Salicaceæ). =953. Order Myricales.=—Shrubs or small trees. Includes the sweet-gale (Myrica gale) in wet places in northern United States and British North America, Myrica cerifera forming thickets on sand dunes along the Atlantic coast, and the sweet-fern (Comptonia peregrina = C. asplenifolia) in the eastern United States in dry soil of hillsides. =954. Order Leitneriales.=—Shrubs or trees. Includes the cork-wood, Leitneria floridana (Leitneriaceæ). =955. Order Juglandales.=—Trees, staminate flowers in aments. The walnut family (Juglandaceæ, examples: walnut, butternut, etc. Juglans; hickory, Hicoria = Carya). =956. Order Fagales.=—Trees and shrubs. Flowers in aments, or the pistillate ones with an involucre which forms a cup in fruit, as in the acorn of the oak. The birch family (Betulaceæ, examples: Betula, birch; Corylus, hazelnut; Alnus, alder, etc.).