21. Sagittaria australis (J. G. Smith) Small, Flora of the Southeastern United States. 45. 1903.
Appalachian arrowhead
Sagittaria longirostra (Micheli) J. G. Smith var. australis J. G. Smith, Bull. Torrey Bot. Club 24: 20. 1897; S. engelmanniana J. G. Smith. subsp. longirostra (Micheli) Bogin
Herbs, perennial, to 130 cm; rhizomes absent; stolons present; corms present. Leaves emersed; petiole 5-winged, 19--85 cm; blade sagittate, 3--19 ´ 2.5--11 cm, basal lobes ± equal to remainder of blade. Inflorescences racemes, of 5--12 whorls, emersed, 10--29 ´ 3--5 cm; peduncles 25--105 cm; bracts distinct or if connate, then less than ΒΌ total length, lanceolate, 7--30 mm, papery, not papillose; fruiting pedicels spreading to ascending, cylindric, 0.3--2.3 cm. Flowers to 3 cm diam.; sepals recurved to spreading, not enclosing flower or fruiting head; filaments cylindric, longer than anthers, glabrous; pistillate pedicellate, without ring of sterile stamens. Fruiting heads 1--2.2 cm diam.; achenes obovoid, without abaxial keel, 2.1--3.2 ´ 1.4--2.3 mm, beaked; faces not tuberculate, wings 0--2, ± entire, glands absent; beak lateral, strongly recurved, 4--17 mm. 2n = 22.
Flowering summer--early fall (Jul--Oct). Slightly basic to slightly acidic ponds, lakes, and swamps; 1--300 m; Ala., Ark., Fla., Ga., Ill., Ind., Iowa, Ky., La., Md., Miss., Mo., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va.
The name Sagittaria longirostra (Micheli) J. G. Smith has been misapplied to S. australis (J. G. Smith) Small (E. O. Beal et al. 1980).
SELECTED REFERENCE
Beal, E. O., S. S. Hooper, and K. Rataj. 1980. Misapplication of the name Sagittaria longirostra (Micheli) J. G. Smith to S. australis (J. G. Smith) Small. Kew Bull. 35: 369--371.
