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..
Glabrous and glaucous; stem slender, erect, leafy, 6'-15' high. Leaves all linear or linear-lanceolate, entire, the lower narrowed into petioles, obtusish at the apex, the upper sessile, acute, 1 1/2'-2 1/2' long, 1 1/2"-2" wide; thyrsus narrow, spike-like, mostly dense; bracts lanceolate, acuminate; pedicels very short; calyx-segments linear-lanceolate, acuminate, 2"-3" long; corolla blue, or nearly white, 8"-10" long, the tube gradually enlarged, the limb somewhat 2-lipped; sterile filament bearded at the summit.
In dry soil, western Nebraska to North Dakota and Montana. May-July.
P. Haydeni S. Wats. Bot. Gaz. 16: 311. 1891.
Glabrous, not at all glaucous or slightly so; stem decumbent, simple or branched, leafy, 1°-2° high. Leaves linear or elongated-lanceolate, entire, sessile and slightly clasping, acute, acuminate, or the lowest obtusish at the apex, 2'-5' long, 1"- 5" wide; thyrsus narrow, dense; bracts ovate or ovate-lanceolate, large, cordate-clasping, acute, or acuminate; fruiting pedicels 2" - 3" long; calyx-segments lanceolate, striate-nerved, acuminate, 3"-5" long; corolla blue, 1' long or more, the tube broadly dilated above the calyx, the limb nearly equally 5-lobed; capsule acute, twice as long as the calyx.
In moist soil, Nebraska, Kansas and Wyoming.