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 lacustris Nutt. Gen. 1: 23. 1818.
Similar to the preceding species in size and foliage, or the leaves rather narrower, sometimes wavy-margined. Flowers blue; perianth-tube only 1/2-1' long, shorter than the bracts and the sometimes yellowish perianth-segments somewhat expanded upward; capsule ovoid, about 8" high, borne on a pedicel of about its own length.
Shores of Lakes Huron, Michigan and Superior. Local. May. Perhaps a race of the preceding species.
Iris verna L. Sp. PI. 39. I753-
Rootstock slender. Stems 1-3' high, usually 1-flow-ered. Leaves narrowly linear, 3'-8' high, 2"-5" wide; flowers violet-blue or rarely white, pedicelled; perianth-segments crestless, the outer about 1 1/2 long, obovate, narrowed into slightly pubescent slender yellow claws, the inner somewhat smaller, glabrous; capsule obtusely triangular, short.
On shaded hillsides and in woods, southern Pennsylvania to Virginia, Kentucky, Alabama and Georgia. Rootstock described as " pungently spicy." Slender Blue-flag. April-May.