PLANTS: Annual, biennial, or perennial herbs. STEMS: l-several, simple or sparsely branched. LEAVES: opposite, sessile, often gradually reduced and scale-like below, rarely forming a basal rosette. FLOWERS: sessile or pedicellate, solitary or in open or congested cymes; calyx of (4-)5(-6) sepals, the lobes minute to well developed, the tube usually with an intracalycine membrane around the upper rim; corolla marcescent, (4-)5(-6)-lobed, funnelform, cylindric, fusiform, or campanulate, the lobes large and prominent to obsolete, the tube with plicate appendages (plicae) between the lobes, these entire or variously toothed or divided; stamens (4-)5(-6); pistil stipitate or sessile with glands at the base. FRUIT: a capsule protruding from or included in the marcescent corolla. SEEDS: numerous, usually with a marginal wing. NOTES: Ca. 200 spp; world-wide, most common in montane areas of the n hemisphere. (For Gentius, King of Illyria). REFERENCES: Mason, Charles T. 1998 Gentianaceae. J. Ariz. - Nev. Acad. Sci. 30(2): 84.
Fls (4)5-merous; cal-tube campanulate, obconic, or tubular, with a membrane or rim around the inside at the summit, the lobes arising from just beneath the rim, well developed or sometimes ±reduced; cor tubular to funnelform or campanulate, sometimes remaining closed, convolute in bud, the lobes alternating with folds or plaits in the sinuses, these often of different color or texture, sometimes as long as or even longer than the proper lobes; a whorl of nectary-glands present around the base of the ovary, not on the cor; ovary ellipsoid to cylindric, often ±stipitate; style short and stout; stigma 2-lobed; seeds many, small; herbs, usually glabrous or only inconspicuously papillate-puberulent, most spp. perennial, ours all from a cluster of fleshy- fibrous to sometimes tuberous-thickened or merely fibrous roots; lvs sessile or subsessile; fls ±showy, blue or less often white, yellowish, or greenish. 300, ±cosmop., except Afr. (Dasystephana)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.