58 NORTH AMERICAN FLORA [VoLuME 17 
21. Sagittaria rigida Pursh, Fl. Am. Sept. 397. 1814. 
Sagiilaria heterophylia Pursh, Fl. Am. Sept. 396. 1814. Not S. heterophylla Schreb. 1811. 
Sagitlaria heterophylia angustifolia Engelm. in A. Gray, Man. ed. 5. 494. 1867. 
Sagittaria heterophylla elliptica Engelm. in A. Gray, Man. ed. 5. 494. 1867. 
Plants emersed and erect or nearly so, or submerged and sometimes greatly elongate; 
leaves various, the phyllodia gradually tapering, the blade-bearing ones usually present, 
the blades 5-20 cm. long, linear, lanceolate, 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; pedicels of the pistillate flowers (1 or 2 lower whorls) 
barely 1 cm. long, or nearly wanting; bracts ovate, obtuse, 4-8 mm. long, united at the 
base; sepals ovate or oblong-ovate, becoming 6~8 mm. long; corolla 2-3 cm. broad or some- 
times smaller; filaments dilated, finely pubescent; anthers very broad, shorter than the 
filaments ; fruit-heads 8-15 mm. in diameter, bristly by the protruding beaks of the achenes ; 
achenes cuneate, 3-4 mm. long, winged, the beak stout, ascending. 
TYPE LOCALITY : Oswego River, New York. 
DISTRIBUTION: Quebec to Minnesota, New Jersey, Tennessee, and Nebraska. 
pl Daa Bot. Mag. p/. 1632; Britt. & Brown, Ill. Fl. f. 201; Rep. Mo. Bot. Gard. 6: 
22. Sagittaria longiloba Engelm. Bot. Mex. Bound. 
Surv. 212. 1858. 
Sagitlaria sagittifolia mexicana Mart. & Gal. Bull. Acad. Roy. Belg. 9?: 379. 1842. Not S. 
mexicana Steud. 1841. 
Plants mostly emersed, 3-15 dm. tall; leaf-blades 9-23 cm. long, the terminal lobe 
linear to lanceolate, the basal lobes linear or linear-lanceolate, twice or thrice as long as 
the terminal one, long-acuminate; scapes simple or rarely branched; whorls of the inflo- 
rescence 4-8 or more, remote, the one to three lower ones with pistillate flowers; pedicels 
slender, 15-35 mm. long, spreading; bracts lanceolate, 6-8 mm. long, acuminate; sepals 
oblong, oval or obovate, becoming 6-7 mm. long; corolla 1.5-2.5 cm. broad; filaments not 
dilated, glabrous; anthers oblong, shorter than the filaments; fruit-heads 10-15 mm. in 
diameter; achenes cuneate, 1 mm. long, the margins somewhat undulate, the beak very 
short, lateral. 
TYPE LOCALITY: San Elceario. . 
DISTRIBUTION : Nebraska and Colorado to Texas and Mexico. 
ILLUSTRATIONS: Rep. Mo. Bot. Gard. 6: f/. 72; Britt. & Brown, Ill. Fl. f 198; Engler, Pflan- 
zenreich 45: f, 74. 
23. Sagittaria Greggii J. G. Smith, Rep. Mo. Bot. Gard. 6: 43. 1894. 
Plants partially emersed, 9-15 dm. tall; leaf-blades hastate, 20-40 cm. long, the ter- 
minal lobe ovate to lanceolate, acute or slightly acuminate, the basal lobes lanceolate or 
linear-lanceolate, acuminate, about as long as the terminal one or longer; scapes 5-angled 
near the base, branched ; whorls of the inflorescence several or many; bracts lanceolate or 
linear-lanceolate, acuminate, 15-30 mm. long ; pedicels of the lower whorls 15-30 mm. 
long, mostly ascending; sepals oval to obovate, becoming 6-8 mm. long; corolla mostly 
1-2 cm. broad, or more; filaments not dilated, glabrous; anthers about as long as the fila- 
ments or shorter; fruit-heads 8-15 mm. in diameter ; achenes obovate to orbicular-obovate, 
2-3 mm. long, thick-margined, the beak minute. 
TYPE LOCALITY: Mexico. : 
DISTRIBUTION: California and Mexico. 
ILLUSTRATION: Rep. Mo. Bot. Gard. 6: pi. 12. 
24. Sagittaria brevirostra Mackenzie & Bush, Rep. Mo. Bot. 
Gard. 16: 102. 1905. 
Sagittaria variabilis diversifolia Engelm. in A. Gray, Man. ed. 5, 493. 1867. 
Plants mostly emersed, 4-8 dim. tall; leaf-blades sagittate, 25-40 cm. long, the terminal 
Jobe lanceolate or linear-lanceolate, acuminate, the basal lobes narrowly lanceolate or almost 
