GENTIANACEAE (gentian family)

Plants annual or perennial herbs (shrubs or small trees elsewhere), sometimes mycoheterotrophic (parasitic on mycorhizal fungi). Leaves simple, mostly opposite or whorled, sessile. Stipules absent, but the bases of leaves at each node usually joined by a transverse line around the stem. Leaf blades sometimes reduced to scales, the margins entire. Inflorescences terminal and/or axillary, of solitary flowers, clusters, racemes, or panicles, the flowers usually subtended by bracts. Flowers actinomorphic (zygomorphic elsewhere), perfect, hypogynous. Calyces with 2, 4, or 5(–14) lobes, sometimes deeply divided to form separate sepals. Corollas with 4 or 5(–14) lobes, frequently bearing nectar glands or scales on the inner (upper) surface, usually spirally twisted in bud. Stamens 4 or 5(–14), attached to corolla tube, alternating with the corolla lobes, the anthers attached near their midpoints or near their bases, distinct or sometimes fused, dehiscing longitudinally. Pistil 1 per flower, of 2 fused carpels, the ovary superior, 1-locular, the placentation parietal. Style 1 per flower (sometimes appearing 2-branched at the tip), the stigma usually 2-lobed. Ovules numerous. Fruits capsules (rarely fleshy), dehiscent longitudinally by 2 valves. 80 genera, 1,100 species, nearly worldwide, especially in montane areas.

A number of genera contain species that are cultivated as oranmentals and several genera also contain species that have been used medicinally.