19.
Sagittaria cuneata
E. Sheldon, Bulletin of the Torrey Botanical Club. 20:283, plate 159. 1893.
Northern arrowhead, wapato, Sagittaria cuneaire
Sagittaria arifolia Nuttall ex J. G. Smith
Herbs, perennial, to 110 cm; rhizomes absent; stolons present; corms present. Leaves emersed, floating, and submersed; submersed phyllodial, flattened, to 45 cm; floating with petiole triangular, to 100 cm, blade cordate or sagittate, rarely linear or ovate, 7.5--9 ´ 3.5--4 cm; emersed with petiole recurved, 3.5--51 cm, blade linear to sagittate, 2.5--17 ´ 1.5--11 cm, basal lobes when present shorter than remainder of blade. Inflorescences racemes, rarely panicles, of 2--10 whorls, emersed, 14--21 ´ 2--10 cm, peduncle triangular, 10--50 cm; bracts connate more than or equal to ¼ total length, lance-attenuate or acute, mostly (4--)7--40 mm, membranous, not papillose; fruiting pedicels ascending, cylindric, 0.5--2 cm. Flowers to 25 mm diam.; sepals recurved, not enclosing flower or fruiting head; filaments not dilated, equal to or longer than anthers, glabrous; pistillate pedicellate, without ring of sterile stamens. Fruiting heads 0.8--1.5 cm diam.; achenes obovoid, abaxially keeled, 1.8--2.6 ´ 1.3--2.5 mm, beaked; face not tuberculate, wings 0--1, ± entire, glands 0--1; beak apical, erect, 0.1--0.4 mm. 2n = 22.
Flowering late spring--summer (Jun--Sep). Calcareous and muddy shores and shallow waters of rivers, lakes, ponds, pastures, and ditches, occasional in tidal waters, or in deep flowing water with slow current; 100--2500 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Labr.), N.W.T., N.S., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.Dak., Ohio, Okla., Oreg., Pa., S.Dak., Tex., Utah, Vt., Wash., Wis., Wyo.
Sagittaria cuneata is extremely variable. On emersed plants, the leaf petioles are often bent toward the ground. Submersed plants often grow from a basal rosette with a long flexuous petiole and a floating sagittate leave. Plants in deep rivers often develop broad, straplike phyllodia.
