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..
Perennial; glabrous; stem terete, 1°-2° high. Leaves rather distant, lanceolate or ovate-lanceolate, acuminate, rounded at the base, smooth-margined, 2'-3' long, the lower narrower and obtuse; flowers about 1 1/2 high in a sessile terminal cluster, 2-bracteolate under the calyx; calyx-lobes unequal, the larger about as long as the tube; corolla greenish blue or bright blue, club-shaped, its lobes ovate, acute or acutish, much longer than the broad 1-2-toothed appendages; anthers coherent, or at length distinct; seeds oblong, winged.
In wet soil, New Brunswick to western Ontario, Michigan and Minnesota. Referred in our first edition to Gentiana rubricaulis Schwein., which proves to be a synonym of the preceding species. Recorded from central New York. Aug.-Sept.
Gentiana villosa L. sp. Pl. 228. 1753. Gentiana ochroleuca Froel. Gent. 35. 1796. D. villosa Small, Fl. SE. U. S. 931. 1903.
Perennial, glabrous or nearly so; stem simple, slender, terete, 6'-18' high. Leaves obovate, obtuse or the upper acute, narrowed at the base, faintly 5-nerved, 1'-3' long, the lower much smaller; flowers several in a terminal sessile cluster and sometimes also in the upper axils, nearly 2' long, 2-bracteolate under the calyx; calyx-lobes unequal, linear, longer than the tube; corolla greenish white, striped within, oblong-funnelform, open, its lobes triangular-ovate or ovate-lanceolate, erect, much longer than the oblique entire or 1-2-toothed appendages; seeds oval, wingless.
Gentiana purpurea Walt. Fl. Car. 109. 1788. Not. L. 1753. Gentiana Porphyrio J. F. Gmel. Syst. 2: 462. 1791. Gentiana angustifolia Michx. Fl. Bor. Am. 1: 177. 1803. D. Porphyrio Small, Fl. SE. U. S. 931. 1903.
Perennial, glabrous; stem erect or ascending, simple or branched, 6'-18' high. Leaves linear, firm, acute or blunt at the apex, 1-2' long, 1-2" wide, or the upper and lower shorter; flowers solitary at the ends of the stem or branches, short-peduncled, about 2' high, not bracteo-late under the calyx; calyx-lobes linear, longer than the tube; corolla funnel form, bright blue, sometimes brown-dotted within, its lobes ovate, acutish, spreading, 5"-7" long, three times as long as the conspicuously laciniate appendages, or more; seeds oblong, wingless.
In moist pine barrens, New Jersey to Florida. Aug.-Oct.