beak minute, 0.1-0.2 mm. long, horizontal or incurved. 

 Swamps and lake shores, Okla.; s.w. Mo., Kan. and Okla. 



7. Sagittaria latifolia Willd. Wapato, Duck-Potato. Figs. 64 and 65. 



Leaves erect or erect-spreading; leaf blades triangular-ovate, obtuse to acute at 

 apex, sagittate, the portion above the basal lobes to 25 cm. long and wide, the 

 linear to ovate-triangular basal lobes one half as long as or longer than the body 

 of the blade; scapes angled, occasionally branching from the lowest whorls, the 

 main axis with as many as 10 whorls, with one or more of the lower whorls 

 pistillate or all unisexual; pedicels of pistillate flowers typically shorter than those 

 of the staminate flowers; sepals to 1 cm. long, glabrous to densely pubescent; 

 bracts cymbiform, distinctly or only slightly connate, thin, somewhat scarious, 

 obtuse to acute, glabrous to densely pubescent; stamens with slender filaments that 

 are usually longer than the anthers; fruiting heads to 25 mm. in diameter; achenes 

 obovate, to 3.5 mm. long and 3 mm. wide, with broad marginal wings but no 

 facial keels; beak broad-based, subhorizontal to slightly incurved, to 2 mm. long. 

 Incl. var. obtusa (Muhl.) Wieg. 



In water or wet places from s.e. to n. Tex. and Okla. (Washita, Logan, Ottawa, 

 Delaware, Woodward, Adair and Choctaw cos.), w. through N.M. (Sandoval Co.) 

 to Ariz. (Navajo Co.), May-Sept.; throughout most of the U. S. and much of 

 Latin Am. 



Both the entirely glabrous widespread var. latifolia and the southern var. 

 pubescens (Muhl.) J. G. Sm. (5. pubescens Muhl.), with densely pubescent bracts 

 and calyx, are rare in our area. Several variants, such as f. hastata (Pursh) 

 Robins, and var. obtusa (Muhl.) Wieg., have been proposed, based on leaf 

 variations. 



8. Sagittaria longiloba Engelm. ex Torr. in J. G. Sm. Flecha de agua. Fig. 66. 

 Leaves erect or erect-spreading; leaf blades ovate-triangular, acute at apex, 



sagittate, the portion above the basal lobes to 15 cm. long and 1 dm. wide, the 

 conspicuously long linear to lanceolate basal lobes always longer than and 

 commonly twice as long as the body of the blade; scapes commonly branching at 

 the lowest whorl, the main axis with as many as 12 whorls; pedicels to 35 mm. 

 long, ascending; bracts ovate-lanceolate to narrowly lanceolate, attenuate, to 

 25 mm. long, connate at base; stamens with glabrous linear filaments to 3 mm. 

 long and exceeding the anthers; fruiting heads to 12 mm. in diameter; achenes 

 obovate, to 2.3 mm. long and 1.3 mm. wide, the narrow dorsal wing to 0.3 mm. 

 wide, the ventral wing nearly obsolete, the faces commonly 1 -winged; beak 

 laterally inserted, triangular, to 0.15 mm. long or obsolete. 



In shallow water of sloughs, ditches, ponds and swamps, especially common 

 in roadside ditches in s. Tex. and extending to n. and w. Tex., Okla., N. M. and 

 Ariz., Apr.-Nov.; Ariz., N. M., Calif.(?), Colo., Kan., Neb., Okla., Tex., and Mex. 



9. Sagittaria Greggii J. G. Sm. Fig. 67. 



Erect aquatic of shallow water, to 1 m. tall; tip of ephemeral rhizome at length 

 becoming a globose perennial corm, or plant behaving as an annual; leaves 

 erect, the blades sagittate, 2-4 dm. long, the basal lobes 2 to 3 times as long 

 as the terminal, linear to linear-lanceolate, sometimes acuminate, the submersed 

 juvenile leaves with blades entire or lacking; inflorescence simple or branched, 

 subequal to or longer than leaves; lower flowers pistillate, upper ones staminate, 

 occasionally a. few flowers perfect; pistillate flowers on slender ascending often 

 unequal pedicels, the pedicels 1-3 cm. long; sepals becoming reflexed, not growing 

 with fruit; petals white, blades orbicular, claws cuneate; rudimentary stamens in 

 a single whorl, sometimes a few with pollen; staminate flowers withering-persistent, 

 rarely with rudimentary pistils; stamens numerous, the filaments longer than 



150 



