PLANTS: Annual, biennial or perennial herbs. STEMS: erect, glabrous. LEAVES sessile and somewhat clasping or petioled, often forming a basal rosette. FLOWERS: 4-merous, large, solitary, sessile or terminal on elongated pedicels, the buds ellipsoid or ovoid-ellipsoid, quadrangular; calyx cylindric-campanulate, the lobes usually in pairs unequal in size and shape; corolla tube cylindric-campanulate; lobes oblong, ovate-oblong, spatulate, the margins entire or the apex erose-dentate becoming fimbriate along the sides and entire toward the base; stamens 4; pistil stipitate, fusiform to cylindric. SEEDS: elliptic to cylindric, densely papillate. NOTES: 26 spp.; n temperate regions of N. Amer and Eurasia, s in mts to c Mex. (Gentian + Greek apsis = appearance). REFERENCES: Mason, Charles T. 1998 Gentianaceae. J. Ariz. - Nev. Acad. Sci. 30(2): 84.