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..
Iris get-manica L. Sp. PI. 38. 1753.
Rootstock thick. Stems stout, usually branched and several-flowered, 2°-3° tall, bearing several leaves. Leaves glaucous, 8"-2' wide, the basal ones mostly shorter than the stem; bracts scarious; flowers nearly sessile in the bracts, large and very showy, deep violet-blue vejned with yellow and brown or sometimes white; outer perianth-segments broadly obovate, 3'-4' long, their claws strongly crested; inner perianth-segments narrower, arching.
Escaped from gardens to roadsides in Massachusetts and Virginia. Native of Europe. May-June.
Rootstock stout, fleshy. Stems rather slender, 2°-3° tall, simple or branched, several-flowered and bearing 2-4 leaves; leaves pale green and somewhat glaucous, shorter than or equalling the stem, 3"-8" wide; pedicels 1/2"-1' long, shorter than the bracts; flowers reddish brown, variegated with blue and green; perianth-segments glabrous, crestless, the outer ones 1 1/2'-2' long, the inner smaller, spreading; style-branches 2"-3' wide.
Iris Pseudacorus L. Sp. PL 38. 1753.
Rootstock thick. Stems 1 1/20-3° high, usually several-flowered; leaves pale green and glaucous, stiff, 4"-8" wide, the lower equalling or longer than the stem; flowers bright yellow, short-pedicelled; perianth-segments glabrous and crestless, the outer broadly obovate, 2'-2 1/2' long, the inner oblong, nearly erect, scarcely longer than the claws of the outer ones; capsule oblong, 2'-3' long.
Iris orientalis Mill., native of Asia, with pale yellow flowers and short stem-leaves, is reported as escaped from cultivation into marshes on the coast of Connecticut.
Iris cristata Ait. Hort. Kew. I: 70. 1789.
Rootstock slender, branched, creeping, tuberous-thickened. Stems only 1' - 3' high, 1-2-flowered; leaves lanceolate, bright green, 4'-9' long, 3"-9" wide, much exceeding the stems; scape flattened, flowers blue, pedicelled; perianth-segments obovate, 1'-1 1/2' long, the outer crested, little longer than the naked inner ones, the tube very slender, 1V-2Y long above the ovary, longer than the bracts; capsule oval, sharply triangular, narrowed at each end, 6"-9' high, 4"-5" thick.
On hillsides and along streams, Maryland to southern Ohio and Indiana, south to Georgia, Tennessee and Missouri. April-May.