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..
S. albidum Raf. Atl. Journ. 17. 1832.
Green and glaucescent, the spathes often purplish, 2° high or less. Leaves half the height of the stems or longer, 1/2"-2" wide, very acute, mostly smooth-edged; stems usually broadly winged, the edges serrulate to smooth; spathes sessile in a close terminal pair, the prominent outer bract l' - 3' long, its edges free to the base; inner bracts acuminate, often cilio-late on the keel, much shorter than the outer; flowers white to pale blue; 4"-6" long; capsules pale, de-pressed-subglobose, 1"-1 1/2" high, on erect-spreading pedicels usually shorter than the inner bracts; seeds globose, 1/2" or less in diameter, umbilicate, distinctly pitted.
Grassy places, Ontario to Wisconsin, Ohio, North Carolina, Arkansas and Mississippi. Also in Connecticut and in southern New York, apparently introduced. April-June.
Stiff and erect, pale and glaucous, 4-20 high. Leaves half the height of the stem or longer, 1/2"-2" wide, acute, the edges minutely serrulate; stem simple or rarely branched, winged, the edges minutely serrulate; spathes green or slightly purplish, the outer bract rarely less than twice the length of the inner one, 2 1/2' long or less, obscurely hyaline-margined, united-clasping at base; inner bract attenuate; flowers deep violet-blue, 5"-6" long; capsules broadly oval to globose, 2"-3" high, dull brown to whitish, often purplish-tinged, on erect pedicels usually shorter than the inner bract.
Fields and hillsides, Newfoundland to Saskatchewan, British Columbia, Virginia, Nebraska, Colorado and Utah. Blue-eyed Mary. Star-eyed grass. Grass-flower. Pigroot. Blue-grass. May-July.
Sisyrinchium septentrionale Bicknell, a diminutive species with large capsules, enters our northwestern limits in North Dakota.
S. mucronatum Michx. Fl. Bor. Am. 2: 33. 1803.
S. intermedium Bicknell, Bull. Torr. Club 26: 498. 1899.
More caespitose than S. angustifolium and decidedly more slender and delicate, with smaller spathes and capsules, sometimes scarcely glaucescent and the spathes often bright red-purple. Stem and leaves from capil-laceous to i" wide, rarely wider, the stems narrowly winged or merely margined; bracts thin, glabrous, hyaline-margined, the outer one slenderly prolonged, united-clasping at base; inner bracts scarious, obtuse to attenuate, gradually emerging from the outer one, flowers deep violet-blue, rarely white, 3"'-7" long; capsules pale and thin-walled, subglobose to obovate-oblong, 1"-2" high, on slender subspreading exserted pedicels.
Fields and meadows, Massachusetts to Michigan, Pennsylvania and Virginia. May-June.