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..
Chelone hirsuta L. Sp. Pl. 611. 1753.
Pentstemon hirsutus Willd. Sp. Pl. 3: 227. 1801.
Stem slender, erect, downy nearly or quite to the base, 1°-3° high. Leaves puberulent or glabrous, denticulate or the uppermost entire, the basal oblong or ovate, obtusish at the apex, 2' - 4 1/2' long, ¥-2' wide, narrowed into petioles, the upper sessile, lanceolate, mostly acuminate, sessile or slightly clasping; inflorescence thyrsoid, rather loose, glandular-pubescent; pedicels mostly short; corolla purplish or violet, the tube gradually dilated above, 2-grooved on the lower side, about 1' long, the throat nearly closed by the villous palate at the base of the lower lip; sterile filament densely bearded for about one-half its length.
Pentstemon laevigatus var. canescens Britton, Mem.
Torr. Club 2: 30. 1890. P. canescens Britton, Mem. Torr. Club 5: 291. 1894.
Densely and finely canescent or puberulent, or the leaves sometimes nearly glabrous; stem rather stout, 1°- 3° high. Leaves denticulate, the lower and basal ones oval, obtuse, narrowed into long margined petioles, the next 1 or 2 pairs contracted below the middle and somewhat fiddle-shaped, 3'-6' long, the upper ovate or ovate-lanceolate, acuminate, clasping; thyrsus elongated, open, glandular-pubescent, leafy-bracted below; pedicels very short; calyx-segments lanceolate, acuminate; corolla purple or nearly white, about 1' long, slightly or not at all bearded in the throat; sterile filament slightly bearded for about one-third its length; capsule ovoid, glabrous, longer than the calyx.
In dry woods, Virginia, West Virginia and North Carolina to western Kentucky. Recorded from Missouri. May-June.
Pentstemon pallidus Small, Fl. SE. U. S. 1060. 1903.
Puberulent, or sometimes canescent-puberulent; stem 3° - 9° tall. Basal and lower stem-leaves with oblong elliptic or nearly spatulate blades; upper stem-leaves few, the blades oblong, lanceolate or linear-lanceolate, rather remotely toothed, partly clasping; panicles narrow; calyx-segments ovate, becoming triangular, acute, closely puberulent or pubescent during anthesis; corolla white or purplish, 9" - 10" long, the tube rather gradually dilated, the throat sparingly bearded; sterile filament bearded with very short hairs.
In sandy soil or swamps, Connecticut and New York to Missouri, Florida and Oklahoma. June-July.