An in vitro culture of marsh gentian (Gentiana pneumonanthe L.) was successfully established from seeds collected in the wild. Seedlings were cultured on 1/2 WPM medium supplemented with 2.25 mg l^-1 BAP and 0.125 mg l^-1 IAA. Following several subcultures, some seedlings flowered in vitro. Shoot explants containing a single node with opposite leaves were used to investigate the influence of node position along the shoot axis on flowering. The flowering gradient along the shoot axis of marsh gentian was determined. The ability to flower in vitro decreased with increased distance from the apex. The highest mean length of flowering shoots has been determined for explants containing the third and fifth node, and the lowest for explants with the seventh node.