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..
Erect mostly glabrous herbs, with opposite or rarely verticillate, entire sessile or short-petioled leaves. Flowers blue, purple, yellow or white, solitary or clustered, terminal or axillary. Calyx tubular, 4-7- (usually 5-) cleft. Corolla tubular, clavate, campanulate, sal-verform or funnelform (rotate in some exotic species), 4-7-lobed, often gland-bearing within, the lobes entire or fimbriate. Stamens as many as the lobes of the corolla and inserted in its tube, included; anthers connate into a tube, or separate, not recurved or coiled. Ovary 1-celled; ovules very numerous; style short or none; stigma cleft into 2 lamellae. Capsule sessile or stipitate, 2-valved. Seeds numerous, sometimes covering the whole inner wall of the capsule, wingless or winged. [Named for King Gentius of Illyria.]
About 150 species, mostly natives of the north temperate and arctic zones and the Andes of South America. Besides the following, some 20 others occur in the western parts of North America.
Type species: Gentiana lutea L.
Corolla-lobes fringed or serrate; flowers 1' - 3' long. Corolla enclosed in the swollen wine-angled calyx.
1. G. ventricosa.
Corolla conspicuously longer than the wingless calyx.
Corolla-lobes fringed all around their summits; leaves lanceolate.
2. G. crinita.
Corolla-lobes fringed mainly on the margins; leaves linear.
Corolla-lobes with entire or rarely denticulate margins; flowers 6 -12 long. Corolla-lobes fimbriate-crested at the base, acute.
4. G. acuta.
Corolla-lobes naked, subulate-acuminate.
Calyx-lobes unequal: flowers mostly 4-parted.
5. G. propinqua.
Calyx-lobes equal; flowers 5-parted.
6. G. quinquefolia.
Gentiana ventricosa Griseb. in Hook. Fl. Bor. Am. 2: 65. pl. 152. 1834.
Annual; stem strict, terete, branched above, about 1° high. Basal leaves obovate, small, those of the stem ovate-oblong, obtuse or acute at the apex, rounded or subcordate at the base, 1' long, 4"-6" wide; flowers few, solitary at the ends of stout peduncles, 4-parted; calyx inflated, ovoid, about 9" high, 4"-5" thick, wing-angled, enclosing the corolla; corolla-lobes oblong, obtuse, lac-erate-serrate; ovary elliptic-oblong.
Grand Rapids of Saskatchewan, between Cumberland House and Hudson Bay (Drummond). Not recently collected.
Gentiana crinita Froel. Gen. 112. 1796.
Annual or biennial; stem leafy, usually branch-eel, 1°-3 1/4° high, the branches erect, somewhat 4-angled. Basal and lower leaves obovate, obtuse, the upper lanceolate or oblong-lanceolate, i'-2 long, acute or acuminate at the apex, sessile by a rounded or subcordate base; flowers mostly 4-parted, several or numerous, about 2' high, solitary at the ends of the usually elongated peduncles; calyx-lobes lanceolate, acuminate, unequal, their midribs decurrent on the angles of the tube; corolla bright blue, rarely white, narrowly campanulate, its lobes obovate, rounded, conspicuously fringed all around their summits, scarcely fringed on the sides, spreading when mature; capsule spindle-shaped, stipitate; seeds scaly-hispid.