Perennial herb 10 cm - 1 m tall

Leaves: opposite, stalkless, stiff, lighter green, oblong or lance-shaped, not long-pointed, widest near the base, with non-toothed, but rough-hairy edges (at least near the base).

Inflorescence: of one to several, often stalkless, erect flowers clustered at the stem apex, and often also in the axils of the upper leaves, or additionally at the ends of short branches. The terminal inflorescence is normally subtended by one or two pairs of large, leaf-like bracts.

Flowers: deep blue, 3 - 5 cm long, radially symmetric, often somewhat open, and subtended by two bracts.

Sepals: five, but fused at base, then separating into over 2 cm long, over 6 mm wide lobes, which are widest near the base.

Petals: five, but fused with shorter, two-toothed, wide membranes (plaits) between the 2 - 7 mm long, rounded-triangular petal lobes. The petal tube is whitish at the base, but becomes more blue upwards.

Stamens: five, attached to the inside of the petal tube.

Pistil: with a single-chambered, superior ovary; a short, stout style; and a two-lobed stigma. There is a whorl of nectar glands present around the base of the ovary, though they are not attached to the fused petal tube base.

Stems: one to several, erect of sometimes slightly decumbent, usually sparsely short-hairy.

Similar species: Gentiana x billingtonii is a hybrid between G. puberulenta and G. andrewsii. The features of this taxon are intermediate between the two parents except that the sepal lobes are longer and wider than in either parent species. Unlike G. x billingtonii, G. andrewsii and its varieties have hairless stems, and the flower plaits, which alternate with the petals, are longer than the petals. While G. puberulenta shares the short-hairy stem with G. x billingtonii, it differs by having much narrower and usually shorter sepal lobes, and the flower plaits are longer and more tapered than in the hybrid. This hybrid is often confused with G. saponaria, but that species has leaves and sepal lobes widest near the middle, less stiff and darker green leaves, and lighter colored flowers. Another similar hybrid is G. x curtisii, which differs by having ridges on the sepal lobes, and more pale to medium blue flowers.

Flowering: August to October

Habitat and ecology: This hybrid can be expected in prairies where both parents, G. puberulenta and G. andrewsii, occur, but it is not common.

Occurence in the Chicago region: native

Etymology: Gentiana is named after Gentius, king of Illyria, who supposedly discovered a medicinal value for the yellow gentian. Billingtonii is named after Cecil Billington, 1876 - 1950, and American botanist.

Author: The Field Museum