8 ELODEACEAE. 



persistent, those of the pistillate flowers reflexed or spreading in our species. 

 Petals 3, white, deciduous. Stamens inserted on the convex receptacle; stami- 

 nate flowers sometimes with imperfect ovaries. Pistillate flowers with numerous 

 distinct ovaries, sometimes with imperfect stamens; ovule solitary; stigmas 

 small, persistent. Achenes numerous, densely aggregated in globose or sub- 

 globose heads, compressed. Seed erect, curved. [Latin, referring to the 

 arrow-shaped leaves of some species.] About 40 species, natives of temperate 

 and tropical regions. Type species: Sagittaria sagittifolia L. 



1. Sagittaria lancifolia L. PL Jam. Pug. 27. 1759. 



Monoecious, glabrous; scape rigid, erect, stout or rather slender, striate, 

 branched or simple, longer than the leaves. Leaves lanceolate or oblong- 

 lanceolate, acute or acuminate at both ends, firm, entire, the blades 5-9-nerved, 

 0.2-0.4 m. long, gradually narrowed into the long petioles, apparently pinnately 

 veined; flowers numerous, 1-2.5 cm. broad; bracts ovate or ovate-lanceolate, 

 usually not united at the base, glabrous or nearly so, equalling or shorter 

 than the fruiting pedicels; stamens numerous; filaments cobwebby -pubescent, 

 equalling or longer than the anthers; achene narrowly obovate-cuneate, 2-3 

 mm. long, winged on both margins, its sides smooth, its beak tapering, oblique. 



In fresh water or slightly brackish swamps and savannas. New Providence. 

 Andros, Great Bahama : Southern United States to Argentina ; Jamaica ; Cuba to 

 Barbadoes. LANCE-LEAVED SAGITTAEIA. 



Order 4. HYDROCHARITALES. 



Floating or more or less emersed herbs, perennial by rootstocks or 

 stolons. Flowers monoecious or dioecious, arising from spathes. Perianth 

 of 2 dissimilar series of parts or the corolla wanting. Stamens 3-12. 

 Carpels 3-15, united. Ovary inferior, with several parietal placentae or 

 several-celled. Endosperm none. 



Ovary 1-celled, with 2-5 parietal placentae ; stigmas 3-5. Fam. 1. ELODEACEAE. 

 Ovary 6-9-celled ; stigmas 6-9. Fam. 2. HYDROCHARITACEAE. 



Family 1. ELODEACEAE Dumort. 

 TAPE-GRASS FAMILY. 



Stoloniferous or rhizomatous aquatics, fresh-water or marine, submerged 

 or the leaves sometimes floating. Leaves various, opposite, verticillate or 

 fascicled. Flowers small, regular or nearly so, monoecious, dioecious or 

 polygamous, enclosed in a spathe composed of 1-3 bracts. Calyx of the 

 pistillate flowers with a tube and 3 lobes or sepals, that of staminate 

 flowers often small or obsolete. Petals 3 or wanting. Stamens 3-12; fila- 

 ments short or the anthers sessile. Pistil 1 ; ovary 1-celled with 2-5 parietal 

 placentae ; ovules usually numerous. Fruit small, indehiscent. Seeds with- 

 out endosperm. 



1. HALOPHILA Thouars; Gaud, in Preyc. Voy. 429. 1829. 

 Submerged or floating marine herbs, with slender rootstocks, branched 

 stems and opposite or whorled, petioled leaves, the dioecious flowers solitary in 

 spathes. Staminate flower peduncled, with 3 sepals, and 3 stamens with nearly 



