This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
1840. I. setosa canadensis Foster, Rhodora 5: 158. 1903.
Rootstock rather slender. Stems slender, simple or branched, terete, 10'-2° tall. Leaves mostly basal, narrowly linear, bright green, shorter than or equalling the stem, 2"-5" wide; flowers solitary or 2 together, violet-blue and white, pedicelled, the pedicels shorter than the bracts; perianth-segments glabrous, crestless, the inner ones involute, oblanceolate, much shorter and smaller than the outer; capsule short-oblong, blunt, l'-1 1/2' long, 7"-10" in diameter, thin-walled, transversely veined, obtusely 3-lobed; seeds in 2 rows in each cavity, about 1 1/2" broad, the raphe prominent.
On river shores, Newfoundland and Labrador to Quebec and Maine. Closely related to the Asiatic Iris setdsa Pall. Summer.
Rootstock stout. Stem rather slender, usually simple, terete, 6'-2° tall, 1-2-flowered; leaves mostly basal, green, sometimes purplish below, shorter than or about equalling the stem, 2"-4" wide; flowers pale blue and variegated, pedicelled; pedicels slender, 1/2'-2' long, usually shorter than the scarious bracts; perianth-segments glabrous, crestless, the outer ones 2r-2 1/2 long, the inner somewhat shorter, the tube 3"-4" long above the ovary; capsule oblong, 1'-1 1/2" long, about 1/2' in diameter, obtusely 6-angled, faintly veined.
In wet soil, South Dakota to Montana, Idaho and Nevada, south to Colorado and Arizona. May-July.
Iris virginica Muhl. Cat. 4. 1813. Not L. 1753. Iris prismatica Pursh, Fl. Am. Sept. 30. 1814. Iris gracilis Bigel. Fl. Bost. 12. 1814. ?Iris Carolina Radius, Schrift. Naturf. Ges. Leipzig 1: 158. 1822.
Rootstock rather slender, tuberous-thickened. Stems slender, often flexuous, 1°-3° tall, usually simple, bearing 2 or 3 leaves; leaves almost grasslike, 1 1/2"-2 1/2" wide, mostly shorter than the stem; flowers solitary or 2 together, blue veined with yellow, slender-pedicelled; pedicels commonly longer than the bracts; outer perianth-segments 1 1/2'-2' long, glabrous and crestless, the inner smaller and narrower, the tube 2"-3' long above the ovary; capsule narrowly oblong, acute at each end, sharply 3-angled, 1'-1 1/2' long, 3"-4" thick; seeds about 1" broad, thick, borne in 1 row in each cavity.
In wet grounds, Nova Scotia to Pennsylvania and Georgia, mainly near the coast. May-June.