1a. Leaves reduced to small scales (1-4 dm. high; flowers small, greenish-yellow, in summer) =Bartonia, Bartonia virginica.= 1b. Leaves rounded, floating (flowers white, summer) =Floating Heart, Nymphoides lacunosum.= 1c. Leaves compound (2-4 dm. high; flowers white or bluish, early summer) =Buckbean, Menyanthes trifoliata.= 1d. Leaves simple, whorled (1-2 m. high; flowers yellowish-white, summer) =American Columbo, Frasera caroliniensis.= 1e. Leaves simple, opposite --2. 2a. Corolla rotate, with spreading lobes, 2-4 cm. broad, pink (5-8 dm. high; summer) =Rose Pink, Sabbatia angularis.= 2b. Corolla bell-shape, each petal with a spur at the base, purplish or white, and not over 1 cm. long (1-4 dm. high; summer) =Spurred Gentian, Halenia deflexa.= 2c. Corolla bell-shape, tubular, funnel-form, or salver-form, not spurred --3. 3a. Corolla-lobes fringed (flowers bright-blue) (Fringed Gentian) --4. 3b. Corolla-lobes entire --5. 4a. Leaves lanceolate (2-8 dm. high; autumn) =Fringed Gentian, Gentiana crinita.= 4b. Leaves linear (1-4 dm. high; late summer) =Fringed Gentian, Gentiana procera.= 5a. Corolla 2 cm. long or a little less --6. 5b. Corolla 2.5-5 cm. long (late summer and autumn) (Gentian) --7. 6a. Upper leaves linear or narrowly lanceolate (2-4 dm. high; flowers pink-purple, late summer) =Centaury, Centaurium umbellatum.= 6b. Upper leaves ovate, with several principal veins (1-5 dm. high; flowers blue, late summer and autumn) =Gentian, Gentiana quinquefolia.= 7a. Calyx-lobes rough or ciliate at the margin (flowers blue, or rarely white) --8. 7b. Calyx-lobes smooth (2-8 dm. high) --10. 8a. Corolla-lobes spreading; leaves narrowly lanceolate, indistinctly veined (2-5 dm. high) =Gentian, Gentiana puberula.= 8b. Corolla-lobes erect or incurved; leaves ovate to ovate-lanceolate, with 3-7 principal veins (3-6 dm. high) --9. 9a. Calyx-lobes equaling or exceeding the calyx-tube =Gentian, Gentiana saponaria.= 9b. Calyx-lobes shorter than the calyx-tube =Gentian, Gentiana andrewsii.= 10a. Leaves ovate or ovate-lanceolate, somewhat cordate at base (flowers greenish-white or yellowish-white) =Gentian, Gentiana flavida.= 10b. Leaves narrowly lanceolate or nearly linear, not cordate (flowers blue) =Gentian, Gentiana linearis.= APOCYNACEAE, the Dogbane Family