2. I. prismática, Pursh. (Slender Blue Flag.) Stem very slender, terete; leaves narrowly linear (2–3´´ wide); flowers slender-peduncled (1½–2´ long), the tube extremely short; ovary 3-angled, each side 2-grooved; capsule sharply triangular. (I. Virginica, Man.; not L.)—Marshes near the coast, Maine to N. C. June.
I. Caroliniàna, Watson, resembling n. 1, but with longer laxer and greener leaves, and the very large seeds in one row in each cell, probably occurs in S. Va.
(Addendum) 2a. I. hexágona, Walt. Stems flexuous, often low and slender (1–3° high), leafy; leaves much exceeding the stem, 6–12´´ broad; flowers solitary and sessile in the axils, large, deep blue, variegated with yellow, purple, and white; tube ½´ long; segments about 3´ long, the inner narrow; capsule oblong-cylindric, 6-angled, 2´ long—Prairies, Ky. (Short) to W. Mo. (Bush), and on the coast from S. Car. southward.
[+][+] Flowers copper-colored or dull reddish-brown; petals widely spreading.
3. I. fúlva, Ker. Stem and leaves as n. 1; tube of the perianth cylindrical, as long as the 6-angled ovary; style-branches narrow. (I. cuprea, Pursh.)—Swamps, S. Ill. and Mo. to La. and Ga. May.
[*][*] Stems low (3–6´ high), from tufted and creeping slender (or here and there tuberous-thickened) rootstocks, 1–3-flowered; tube of the perianth long and slender; the violet-blue divisions nearly equal.
4. I. vérna, L. (Dwarf Iris.) Leaves linear, grass-like, rather glaucous; the thread-like tube of the perianth about the length of the divisions, which are oblong-obovate and on slender claws, the outer ones slightly hairy down the orange-yellow base, crestless; capsule obtusely triangular.—Wooded hillsides, Lancaster Co., Penn., to S. C., west to Ky. and Ala. April.—Flowers sometimes white with yellowish centre.
5. I. cristàta, Ait. (Crested Dwarf Iris.) Leaves lanceolate (3–5´ long when grown); those of the spathe ovate-lanceolate, shorter than the thread-like tube of the perianth, which is 2´ long and much longer than the light blue obovate short-clawed divisions, the outer ones crested but beardless; capsule sharply triangular.—In the mountains from Md. to N. C.; Trumbull Co., Ohio (Ingraham); knobs of S. Ind. May.—Flowers fragrant.
6. I. lacústris, Nutt. (Lake Dwarf Iris.) Tube of the perianth rather shorter than the divisions (yellowish, ½–¾´ long), dilated upward, not exceeding the spathe; otherwise as in the last, and too near it.—Gravelly shores of Lakes Huron and Michigan. May.
I. Pseudácorus, L., the Yellow Iris of European marshes, with very long linear leaves and bright yellow beardless flowers, is reported as having become established in Mass. and N. Y.