ALISMACEAE 



45 



12. Sagittaria papillosa Buch. Monoecious. Leaf -blades linear or linear-lanceo- 

 late, 10-15 cm. long, acute, as long as the petioles or shorter : scapes 3-5 dm. tall : whorls 

 of the inflorescence 3-10, the lower remote : pedicels of pistillate flowers 1-1.5 cm. long : 

 bracts ovate, 3-4 mm. long, densely granular-papillose, united to about the middle : sepals 

 ovate, roughened like the bracts : corollas 2-3 cm. broad : filaments not dilated, glabrous : 

 mature fruiting heads subglobose, 6-10 mm. in diameter : achenes cuneate, 1.5 mm. long ; 

 beak lateral and slightly above the middle of the body. 



In shallow ponds, Louisiana and Texas. Spring to fall. . 



13. Sagittaria ambigua J. G. Smith. Monoecious. Leaves erect ; blades lanceo- 

 late, 12-50 cm. long, 5-nerved, shorter than the petioles : scapes 3-6 dm. tall, as long as 

 the leaves or surpassing them : whorls numerous, commonly 8-15 : pedicels mostly ascend- 

 ing, those of the pistillate heads longer than those of staminate ; bracts lanceolate, 10-15 

 mm. long, united at the bases : filaments not dilated, glabrous : achenes oblong, slightly 

 curved, 2 mm. long, narrowly winged, prolonged into short horizontal beaks at the top. 



In ponds, Kansas and Oklahoma. Summer. 



14. Sagittaria lancif olia L. Monoecious. Leaves 4-9 dm. tall ; blades leathery, 

 broadly linear to elliptic, 3-6 dm. long, acute, commonly shorter than the petioles : scapes 

 6-20 dm. tall, usually branched : whorls of the inflorescence numerous : pedicels of the 

 pistillate heads ascending, often shorter than those of the staminate : bracts ovate or ovate- 

 lanceolate, 1-2.5 cm. long, acute or acuminate : sepals obtuse : corollas 4-5 cm. broad ; 

 petals obovate : filaments not dilated, pubescent : mature fruiting heads fully 1 cm. in diam- 

 eter : achenes cuneate or obovate, 2-3 mm. long, winged ; beak short, ascending. 



In marshes, Delaware to Florida, Texas and tropical America. Spring and summer. 



15. Sagittaria rigida Pursh. Monoecious. Leaf-blades 5-20 cm. long, linear, lance- 

 olate, elliptic or broadly ovate, 7-9-nerved, acute or cordate at the base, sometimes with 

 1 or 2 spreading or recurved basal lobes : scapes 1-8 dm. long, commonly shorter than the 

 leaves, usually bent and sometimes branched at the lower whorl of the inflorescence : pedi- 

 cels of the pistillate heads (1 or 2 lower whorls) barely 1 cm. long : bracts ovate, obtuse, 

 4-8 mm. long, united at the base : mature fruiting heads 8-15 mm. in diameter, bristly by 

 the protruding beaks of the achenes : achenes cuneate, 3-4 mm. long, winged ; beak stout, 

 ascending. 



In swamps or running water, Quebec to Minnesota, New Jersey, Tennessee and Nebraska. Sum- 

 mer and fall. 



16. Sagittaria longiloba Engelm. Monoecious, glabrous. Leaf-blades 10-18 cm. 

 long ; terminal lobe linear to lanceolate ; basal lobes linear or linear-lanceolate, twice or 

 thrice as long as the terminal one, long-acuminate : scapes 3-15 dm. tall, rarely branched : 

 whorls of the inflorescence 4-8, remote, 1-3 lower very fertile : pedicels slender, 15-35 mm. 

 long, spreading : bracts lanceolate, 6-8 mm. long, acuminate : filaments not dilated, gla- 

 brous : mature fruiting heads 10-15 mm. in diameter : achenes cuneate, 1 mm. long ; wings 

 somewhat undulate ; beak very short, lateral. 



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



17. Sagittaria longirdstra (Micheli) J. G. Smith. Monoecious, glabrous. Leaf- 

 blades rather ample, 10-25 cm. long ; terminal lobe broadly ovate, abruptly pointed ; basal 

 lobes ovate or oblong-lanceolate, acute, about J as long as the blade : scapes 4-8 dm. tall, 

 sharply 6-angled : whorls of the inflorescence few, 1 or 2 lower ones usually pistillate : 

 bracts triangular, 15-30 mm. long, acuminate : pedicels of the lower whorls 5-10 mm. 

 long, ascending: mature fruiting heads spheroidal, 12-18 mm. in diameter: achenes 

 obovate, 4 mm. long, the crest undulate ; beak about as long as the body, curved ; facial 

 wings prominent. 



On margins of ponds, New Jersey and Pennsylvania to Tennessee. Summer. 



18. Sagittaria viscosa C. Mohr. Monoecious. Leaf -blades broadly ovate, 2-3.5 dm. 

 long, rounded to the apiculate apex ; basal lobes ovate, acute or acuminate, shorter than 

 the middle lobe : scapes 5-8 dm. tall, overtopping the leaves : pedicels in 8-10 whorls, of 

 nearly equal length throughout : bracts leathery, ovate-oblong, obtuse, papillose, rugose 

 and viscid : sepals leathery, ovate-lanceolate, roughened and viscid like the bracts : corol- 

 las white, fully 1 cm. broad : filaments not dilated, pubescent : achenes not seen. 



In muddy plases and marshes, southern Alabama. Spring and summer. 



19. Sagittaria australis (J. G. Smith) Small. Monoecious, slender. Leaf-blades 

 oval or suborbicular, 8-10 cm. long, abruptly pointed at the apex, ciliate ; basal lobes 

 ovate, barely J as long as the blade, obtuse : scapes 4-5 dm. tall, pubescent about the 

 nodes in the inflorescence, angled, overtopping the leaves : whorls of the inflorescence 4-6, 

 remote : bracts lanceolate or ovate-lanceolate : pedicels of lower whorls 10-13 mm. long : 

 achenes obovate, 3-3.5 mm. long ; crest undulate ; beak curved over the top of the crest, J 



