Plants of the Eloise Butler Wildflower Garden

The blue closed Gentians in the Garden are of two similar species, differing only in the flower. The Bottle Gentians are an erect native perennial forb, growing on smooth stems 1 to 3 feet high, usually unbranched, but with multiple stems from the root.

The leaves are opposite, medium green, smooth, lance shaped, twice as long as wide, with parallel veins, mostly stalkless and usually pointed at the tip. Leaves at the top of the stem below the terminal flower cluster usually form a whorl. Leaves turn a nice purple in the autumn.

The inflorescence is a cluster of stalkless flowers at the top of the erect stem and sometimes also in the upper leaf axils.

The flowers have a 1 1/4 to 1 3/4 inch long tube shaped corolla of 5 blue lobes forming petals that are fused together by a connecting fringe, creating folds between the outside of the petals. (White albinos are known to occur). In the species G. clausa the petals remain closed at the tip with those fringes hidden by the closed tip. In the species G. andrewsii, (predominant in the photos below) the fringes of the flower lobes are longer than the petals and thus are visible at the tip of the closed flower. Flower color varies by age of the blooms and amount of sun, shading to a bronze as they age. The flower calyx is much shorter than the corolla and has ovate lobes with pointed tips. There are 2 small bracts under the calyx. The reproductive parts include 5 stamens that rise from around the base of the ovary. These have greenish-white filaments and yellow anthers. The ovary has single style that has a branched tip. The stamens are held against the ovary (but not united with it), with the anthers surrounding the style. As the ovary enlarges with fertilization it becomes ovate to elliptical, somewhat flattened while the stamens wither away.

Seeds: Fertile flowers produce a 2-sectioned seed capsule that splits when mature to release numerous very small flattened brown seeds to the wind. They have no pappus but are light enough (280,000 to the ounce) for wind distribution. Seeds need light for germination plus 60 days of cold stratification and for light, need to be surface sown.

Pollination: Only large bees such as the bumblebee can force open the flower tip of the corolla for pollination. A detailed study of this was published by Ohio State University in 1988. (PDF of article).

Habitat: Bottle Gentian grows in well drained soils of moist meadows, prairies and open woods with full sun to partial shade, however in partial shade the flower stems may not remain fully erect. It tolerates wet-mesic to mesic conditions. The root system is rhizomatous and from the rhizomes the plant can reproduce.

Names: The genus Gentiana is named after King Gentius of Illyria who, according to Pliny, discovered that the roots of certain Gentian species have medicinal qualities for treating malaria. The species name clausa is Latin referring to "closed." The name andrewsii is an honorary for Henry C. Andrews, an English botanical artist of the 1800's. The author name for the clausa plant classification ‘Raf.’ is for Constantine Samuel Rafinesque, (1783-1840), European polymath who traveled in the United States, lived here many years, collected specimens, and published over 6,700 binomial names for plants. He applied to be botanist on the Lewis & Clark expedition but Jefferson turned him down in favor of training Lewis to act as botanist and saving the expense of another person. The second species author ‘Griseb.’ is for August Grisebach (1814-1879), German botanist, professor at Gottingen, publisher of Flora of the British West Indies and whose work specialized in the Gentianaceae and Malpighiaceae.

Comparisons: Bottle Gentian is similar in appearance to the white flowered Plain Gentian, G. alba, except for the flower color. Bottle Gentian is less tolerant of dry conditions than Plain Gentian.