$8 JPLORA. 



sterile ones; stamens numerous, the filaments longer than the anthers; achene 

 about 2 mm. long, quadrate-obovate, somewhat broader above than below, winged 

 on both margins, its beak exceedingly short. In shallow water, Neb. to Colo., south 

 to Tex. and Mex. 



7. Sagittaria ambigua J. G. Smith. KANSAS SAGITTARIA. (I. F. f. 199.) 

 Monoecious; glabrous; scape erector ascending, 0.3-0.6 m. high. Leaves lanceolate, 

 entire, long-petioled, acute or acuminate at both ends, seemingly pinnately veined, 

 really 5-7 -nerved, 12-20 cm. long, equalling or shorter than the scape ; bracts 

 lanceolate, acuminate, 1-1.6 cm. long, much shorter than the slender fruiting pedi- 

 cels, connate at the base, papillose; stamens 20-25; filaments glabrous, longer than 

 the anthers; achene about 2 mm. long, oblong, curved, narrowly winged on both 

 margins, its sides smooth and even, its beak short, oblique. In ponds, Kan. and 

 the Ind. Terr. 



8. Sagittaria lancifolia L. LANCED-LEAVED SAGITTARIA. (I. F. f. 200.) 

 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, en tire, the blades 5 9-nerved, 0.2-0.4 m - l n g> 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, gla- 

 brous or nearly so, equalling or shorter than the fruiting pedicels; stamens numer- 

 ous; 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 swamps and shallow water, Del. to Fla. and Tex., 

 near the coast. Widely distributed in tropical America. 



9. Sagittaria rigida Pursh. SESSILE-FRUITED. ARROW-HEAD. (I. F. f. 201.) 

 Monoecious, glabrous; scape simple, weak, curving, ascending or decumbent, 

 shorter than the leaves. Leaves very variable, linear, lanceolate, elliptic or broadly 

 ovate, acute or obtuse at the apex, entire or with I or 2 short or slender basal lobes; 

 bracts ovate, obtuse, 4-8 mm. long, united at'the base or sometimes distinct; heads of 

 fruit sessile or very nearly so; pedicels of the sterile flowers 1-2.5 cm - l n g! filaments 

 dilated, mostly longer than the anthers, pubescent; achene narrowly obovate, 3-4 

 mm. long, winged on both margins, crested above, tipped with a stout nearly erect, 

 beak of about one-fourth its length. In swamps and shallow water, Quebec to Minn., 

 N. J., Tenn., Mo. and Neb. July-Sept. (S. heterophylla Pursh.) 



10. Sagittaria teres S. Wats. SLENDER SAGITTARIA. (I. F. f. 202.) 

 Monoecious; glabrous; scape slender, erect, simple, 1.5-4.5 dm. long, bearing only 

 1-3 verticils of flowers. Leaves usually reduced to elongated terete nodose 

 phyllodes or some of them short and bract-like, one or two of the longer ones occa- 

 sionally bearing a linear blade; bracts ovate, obtuse, about 3 mm. long, much 

 shorter than the filiform fruiting pedicels, which are longer than the sterile ones; 

 flowers 12-16 mm. broad; stamens about 12, their dilated filaments pubescent, 

 shorter than the anthers; achene broadly obovate, 2 mm. long, the ventral margin 

 winged, the dorsal 7-1 1 -crested, the sides bearing several crenate crests, the beak 

 short, erect. In ponds, Mass, to S. Car. Aug. -Sept. 



11. Sagittaria Eatoni J. G. Smith. EATON'S SAGITTARIA. Monoecious, 

 o. 1-0.2 m. high, glabrous; scape simple, slender, ascending, weak, bearing I, 2, 

 or rarely 3 verticils of flowers. Leaves mostly bladeless phyllodes, rarely with 

 linear-lanceolate, acute or acuminate blades 1.8-3 cm l n g 2 ~4 mm - wide; the 

 phyllodes flat, nodeless ; lowest verticil with two fertile flowers, and one stam- 

 inate; fertile pedicels 4-8 mm. long, shorter than the sterile ones, very slender; 

 sepals ovate-lanceolate, obtuse, 4 mm. long; petals white, with a rose-colored spot 

 at the base, obovate-cuneiform, emarginate; stamens 12; mature achenes not known ; 

 pistils very minute, 80-100. Ripple-swept, sandy shores, between high and low 

 tide, above the influence of salt water, Newburyport, Mass. 



12 Sagittaria cristata Engelm. CRESTED SAGITTARIA. (I. F. f. 203.) 

 Monoecious; scape slender, erect, 0.3-0.8 m. high, simple, bearing 4 or 5 verticils 

 of flowers at or above the surface of the water. Leaves long-petioled, spongy and 

 rigid, reduced to slender phyllodes or bearing linear-lanceolate or elliptic blades 

 5-10 cm. long, and 6-25 mm. wide; bracts acute, 4-8 mm. long, much shorter than 

 the slender fertile pedicels; flowers 1.6-2 cm. broad; stamens about 24; filaments 

 dilated, pubescent^ at least at the middle, longer than the anthers; achene obliquely 



