Engelmann's Arrowhead

Herbs, perennial, to 70 cm; rhizomes absent; stolons present; corms present. Leaves emersed; petiole triangular, 10--40 cm; blade sagittate, 4.5--10 ´ 0.2--2 cm, basal lobes ± equal to remainder of blade. Inflorescences racemes, of 2--4 whorls, emersed, 5--14 X 2--4 cm; peduncles 20--38 cm; bracts distinct or if connate, then less than ¼ total length, lanceolate, 5--25 mm, not papillose; fruiting pedicels spreading, cylindric, 1.5--3.5 cm. Flowers to 30 mm diam.; sepals recurved to spreading, not enclosing flower or fruiting head; filaments linear, longer than to equal length of anther, glabrous; pistillate pedicellate, without ring of sterile stamens. Fruiting heads 1--1.8 cm diam.; achenes cuneate to obovoid, without abaxial keel, 2.4--4 ´ 1.5--3.8 mm, beaked; faces not tuberculate, wings 1--3, ± entire, glands 1--2; beak lateral, obliquely ascending, (0.7--)1--2.1 mm. 2n = 22.

Ont.; Ala., Conn., Del., Fla., Ga., Md., Mass., Miss., N.J., N.Y., N.C., Pa., R.I., S.C., Va.

Flowering late spring--summer (Jun--Sep).

Acid waters of ponds, lakes, bogs, and streams; 0--1100m.

Sagittaria engelmanniana (Engelmann's arrowhead or acid-water arrowhead) is an aquatic plant species native to eastern North America. It has been reported from every state bordering on the Gulf of Mexico or on the Atlantic Ocean from Mississippi to Massachusetts, plus Vermont and Ontario.

Sagittaria engelmanniana occurs in wetlands, predominantly those with acidic water such as Sphagnum bogs. It is a perennial herb up to 70 cm tall. Leaves are sagittate (arrow-shaped) with 3 very narrow lobes.