46 ALISMACEAE 



14. Sagittaria lancifolia L. Leaf-blades elliptic or nearly so to narrowly 

 elliptic-lanceolate, 30-60 cm. long, mainly 5-9-nerved: pedicels of pistillate flowers 

 relatively long, their bracts of a lanceolate type: achenes 2.5-3 mm. long. 



In marshes, Florida to Texas and Mexico. Also in tropical America. 



15. Sagittaria angustifblla Lindl. Leaf -blades linear or nearly so, sometimes 

 very narrow, 9-40 cm. long: scapes as long as the leaves or longer, usually simple, 

 with several flower-whorls, their bracts of a lanceolate type: fruit-heads 1-1.5 cm. 

 thick: achenes 2-2.5 mm. long, abruptly narrowed into the minute beak, the dorsal 

 wing usually crested. 



In low grounds or swamps, Georgia to Mississippi. Also in tropical America. 



16. Sagittaria macrocdrpa J. G. Smith. Leaf -blades linear or linear-lanceolate, 

 5-7 cm. long: scapes 2-4.5 dm. tall, with 3-5 flower-whorls, the flowers of the lowest 

 whorl or the 2 lower whorls pistillate: fruit-heads 10-12 mm. thick: achenes 3 mm. 

 long, winged, the beak ascending. 



On the margins of ponds and streams. North Carolina and South Carolina. 



17. Sagittaria rigida Pursh. Leaf-blades linear to broadly ovate, sometimes 



with basal lobes, 5-20 cm. long: scapes weak, 1-8 dm. long, with 5-9 flower-whorls: 



fruit-heads 8-15 mm. thick, sessile or nearly so: achenes 3-4 mm. long, winged, the 



beak ascending. 



In swamps and running water, Quebec to Minnesota, New Jersey, Tennessee and 

 Nebraska. 



18. Sagittaria longiloba Engelm. Leaf -blades 10-18 cm. long, the terminal 

 lobe linear to lanceolate, the basal lobes narrower and longer: scapes 3-15 dm. tall, 

 with 4-8 remote flower-whorls: fruit-heads 10-15 mm. thick, long-pedicelled : achenes 

 1 mm. long, without facial wings, the dorsal wing somewhat undulate, the beak very 

 short, lateral. 



On margins of shallow ponds, Nebraska and Colorado to Texas and Mexico. 



19. Sagittaria pub^scens Muhl. Leaf -blades 8-25 cm. long, with the terminal 

 lobe more rounded than in no. 20, puberulent or hirsute: scapes 3-6 dm. tall: pedicels 

 of pistillate flowers about as long as the obtuse bracts or slightly longer: sepals not 

 accrescent: fruit-heads 8^15 mm. thick: achenes 2-3 mm. long, the beak horizontal 

 or somewhat declined. 



In meadows and marshes, New Jersey and Pennsylvania to Tennessee and Florida. 



20. Sagittaria latifolia Willd. Leaf-blades broad, 15-40 cm. long, glabrous, 



the basal lobes narrower and rather shorter than the terminal one: scapes 3-6 dm. 



tall: pedicels of pistillate flowers much longer than the acute bracts: fruit-heads 



15-30 mm. thick: achenes about 3 mm. long, the beak ascending or recurved. 



In swamps and shallow water, New Brunswick and Nova Scotia to British Columbia, 

 Florida, California and Central America. 



21. Sagittaria viscosa C. Mohr. Leaf-blades 20-35 cm. long, the middle lobe 

 broadly ovate, the basal lobes shorter, acute or acuminate: scapes 5-8 dm. tall, with 

 few flower-whorls: bracts obtuse: fruit-heads not seen. 



In muddy places and marshes, southern Alabama and Florida. 



22. Sagittaria longirdstra (Micheli) J. G. Smith. Leaf-blades 10-25 cm. 



long, the terminal lobe broadly ovate, the basal lobes as long but narrower: scapes 



4-8 cm. tall, with few flower-whorls: bracts acuminate: fruit-heads 12-18 mm. thick, 



short-pedicelled : achenes 4 mm. long, with facial wings, the dorsal wing partially 



crenate, the beak erect. 



On margins of ponds and streams, New Jersey and Pennsylvania to Florida and 

 Alabama. — Plants from the Southern States, referred to S. Engelmanniana in the first 

 edition of this work appear to be slender-leaved forms of S. longirdstra. 



23. Sagittaria austr^lis (J. G. Smith) Small. Leaf -blades 8-10 cm. long, the 

 terminal lobe very broad, the basal lobes shorter, obtuse: scapes 4-5 dm. tall, with 

 4-6 flower-whorls: fruit-heads fully 10 mm. thick: achenes 3-3.5 mm. long, with facial 

 wings, the dorsal wing undulate, the beak curved over the crest. 



In low grounds, Alabama. 



24. Sagittaria Montevid6nsis C. & S. Leaf -blades 1-5 dm. long, the basal 



lobes narrower and shorter than the ovate terminal one: scapes very stout, about as 



tall as the leaves, the pedicels relatively short: fruit-heads 15-30 mm. thick: achenes 



2-3 mm. long, the slender beak oblique. 



In low grounds and swamps, North Carolina to Florida and Alabama, and in California. 

 Naturalized from South America. 



Order 4. HYDROCHARITALES. 



Perennial aquatic herbs, with rootstocks. Leaves usually with blades. 



