Species Native to Missouri
Common Name: gentian
Type: Herbaceous perennial
Family: Gentianaceae
Native Range: Central North America
Zone: 3 to 7
Height: 2.00 to 3.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: August to October
Bloom Description: White to yellowish white to greenish white
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Flower: Showy
Culture
Grow in average, medium moisture, well-drained soils in full sun to part shade. Best performance is in moist, humus-rich but gravelly, well-drained soils with some part afternoon shade. Best flowering often occurs in full sun, but full sun in the heat of summer may bleach the leaves. Tolerates slightly alkaline soils. Some tolerance for dry soils. Plants prefer cool summer conditions and often perform poorly south of USDA Zone 7.
Noteworthy Characteristics
Gentiana alba is a white-flowered gentian that is native from Manitoba and Ontario south to Oklahoma, Arkansas, Kentucky and North Carolina. In Missouri, it is found in scattered locations throughout much of the State primarily on rocky prairies, wooded slopes, ledges and bluff escarpments, rocky limestone glades and open wooded areas (Steyermark). It typically grows to 2' tall on unbranched stems clad with mostly stalkless, ovate-lanceolate, light yellowish-green leaves (to 3" long). Five-petaled, tube-shaped, upward-facing flowers (to 1 1/2" long) bloom in clusters of 2 to 7 at the stem tips and in the upper leaf axils from August to early October. Flowers range in color from white to greenish white to yellowish white, as reflected in the numerous common names for this plant including white gentian, white prairie gentian, cream gentian, pale gentian and yellow gentian. Flowers lack fragrance. Gentiana alba was first published by Muhlenberg in 1818. Gentiana flavida was first published by Gray in 1846. The plants are synonymous. Some experts consider G. alba to be the correct name because it was published first, but other experts consider G. flavida to be the correct name because of a belief that the Muhlenberg publication was invalid under the International Code of Botanical Nomenclature.
Genus name honors King Gentius of Illyria (reign c. 180-168) B.C., who was reputed to have discovered the medicinal virtues of the root of the yellow gentian or bitterwort (G. lutea) from which a tonic bitters is still made.
Specific epithet comes from Latin meaning white.
Problems
No serious insect or disease problems. Gentian can be a difficult plant to grow well in gardens in the St. Louis area in large part because of the hot and humid summer conditions.
Uses
Rock gardens. Border fronts. Native plant gardens.