Short-lived perennial herb 1 - 2.5 m tall Stem: tall, stout, and hairless. Leaves: in whorls of four (rarely three or five), quite large (lowest ones up to 40 cm long), much longer than wide, a bit narrower near the base, widest above the middle, and very veiny. Inflorescence: large, much branched (lower branches 5 - 15 cm long), pyramid-shaped, loosely flowered, with long (to 10 cm), bract-like leaves below each branch. Flowers: 2 - 3.5 cm wide, light greenish yellow with brown-purple dots, radially symmetric, with a short tube, and four petal lobes flexed at right angles to that tube. Sepals: four or five, but fused at base, then separating into narrow, lance-shaped, usually less than 1 cm long lobes. Petals: four, but fused into a short tube, then separating into 1 - 1.8 cm long, elongate egg-shaped lobes with abruptly pointed tips, and conspicuous, circular, fringed, nectar glands below the middle each lobe. Stamens: usually four, but the base of the awl-shaped filaments fused, and the oblong anthers separate. Pistil: with a single-chambered, superior ovary; a single, persistent style; and a two-lobed stigma. Fruit: a single-chambered, 1.5 - 2 cm long, elliptic or oval, much flattened capsule with flat valves, and four to fourteen seeds. Seeds: large, flat, and with a winged edge.
Similar species: Superficially Frasera caroliniensis resembles a Hypericum (members of a genus in the Clusiaceae or St. John's Wort family), but those plants have flowers with entirely separate petals, and more than one style per flower. Frasera caroliniensis has the petals joined at the base in a short tube, and there is only a single style from the ovary.
Flowering: May to June
Habitat and ecology: Rare, and quite localized in our area to sandy woodlands and rich woods, usually preferring calcareous soils.
Occurence in the Chicago region: native
Notes: This is by far the largest member of the Gentianaceae family in the Chicago Region.
Short-lived perennial 1-2 m; lower lvs oblanceolate, to 4 dm, in whorls of (3)4(5), the upper progressively smaller; infl paniculiform, the lower branches 5-15 cm, the lower bracteal lvs to 10 cm; cor greenish-yellow, purple-dotted, the lance-ovate lobes acute, 10-18 mm, each bearing below the middle a large elliptic gland surrounded by a long fringe; fr elliptic, flat, 1.5-2 cm; 2n=78. Rich woods; w. N.Y. to S.C. and n. Ga., w. to Mich., Ill., Mo., e. Okla., and La. May, June. (Swertia c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.