This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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..
Myosotis scorpioides var. arvensis L. Sp. Pl. 131. 1753. Myosotis arvensis Hill, Veg. Syst. 7: 55. 1764.
Annual or biennial, hirsute-pubescent; stem erect, branched, 6-18' high. Basal and lower leaves ob-lanceolate, obtuse, petioled or sessile; stem leaves mostly oblong or oblong-lanceolate, obtuse or acutish at the apex, narrowed to the sessile base, 1/2'-1 1/2' long, 2"-4" wide; racemes loosely flowered; fruiting pedicels longer than the calyx; hairs of the calyx, or some of them, with minutely hooked tips, the lobes equal, erect, or connivent in fruit, triangular-lanceolate, acute, about as long as the tube; corolla blue or white, the limb concave, l"-1 1/2" broad; nutlets convex on the outer side, somewhat keeled on the inner.
In fields, Newfoundland to western Ontario and Minnesota, south to West Virginia. Perhaps not indigenous. Also in Europe. June-Aug.
M. arvensis var. (?) versicolor Pers. Syn. 1: 156.
Annual, hirsute-pubescent, with mostly straight hairs, often much branched above; stems slender, erect or ascending, 4'-12' high. Leaves oblong, obtuse or obtusish, sessile, or nearly so, or the lower spatulate and narrowed into margined petioles; racemes slender, mostly naked below; pedicels shorter than the fruiting calyx, appressed-pubescent, erect; calyx equally 5-cleft, the lobes iinear-lanceolate, erect or connivent in fruit, longer than or equalling the tube, the hairs, or some of them, with minutely hooked tips; corolla pale yellow changing to violet and blue, its limb about 1" broad; nutlets convex on the outer, slightly keeled on the inner side, shorter than the style.
In fields and along roadsides, southern New York and Delaware. Naturalized from Europe. May-July.
Myosotis micrantha Pall.; Lehm. Neue Schr. Naturf. Ges. Halle 32: 24. 1817.
Annual or biennial, 8' high or less, branched from near the base, the pubescence of both straight and hooked hairs. Leaves oblong to lanceolate, mostly sessile, obtuse or obtusish; racemes slender, distantly flowered to the base; pedicels much shorter than the calyx, pubescent, and usually with some hooked hairs; calyx equally 5-cleft, about as long as the corolla-tube; style not longer than the nutlets.
Fields and roadsides, Ontario to Massachusetts and Ohio. May-July. Naturalized from Europe. Has been mistaken in America for M. collina Hoffm.
Lycopsis virginica L. Sp. Pl. 139. 1753.
Myosotis vema Nutt. Gen. 2: Add. 1818.
Myosotis virginica B.S.P. Prel. Cat. N. Y. 37. 1888.
Annual or biennial, hirsute-pubescent or hispid, erect, branched, 3'-15' high, the branches erect. Leaves oblong or linear-oblong, sessile, 3"-12" long, obtuse, or the lower spatulate and narrowed into short petioles; racemes usually bracted at the base, strict; pedicels ascending or erect, or slightly spreading at the apex, shorter than the fruiting calyx; calyx somewhat 2- lipped, unequally 5-cleft, the lobes lanceolate, acute, longer than the tube, connivent in fruit, very hispid, the hairs, or most of them, with minutely hooked tips; corolla white, the limb 1 1/2" broad or less; nutlets convex on the back, slightly keeled and margined on the inner side.
On dry hills and banks, Maine and Ontario to Minnesota, Florida and Texas. Forget-me-not. April-June.