Frasera caroliniensis Walter

American Columbo

© SRTurner

Family - Gentianaceae

Habit - Perennial, monocarpic forb, producing an aerial stem only at the onset of floral development.

Leaf - Basal rosettes present prior to flowering. Cauline leaves whorled in groups of 4-5, 10-20 cm long, becoming progressively smaller upward, grading into linear bracts in inflorescence.

	Vegetative rosettes.
© JRAbbott

Stem - Flowering stem erect, to 2.5 m, thick, hollow, glabrous, green to purplish.

	Flowering stem.
© SRTurner

	Cauline leaf.
© SRTurner

Inflorescence - Appearing as large, conic or conic-elliptic, highly branched panicle. Consists of numerous smaller, mostly axillary panicles.

	Inflorescence.
© SRTurner

Calyx - Calyces lobed nearly to base, the lobes linear-lanceolate, 6-10 mm long.

	Calyx.
© SRTurner

Flower - Tetramerous. Corollas greenish yellow to nearly white, purple-dotted, deeply lobed, the lobes 10-14 mm long, each lobe bearing a large, fringed, purple nectary gland near the middle of the upper surface. Filaments of stamens elongate, connate at base. Ovaries ovoid, the style elongate, persistent in fruit, the stigma capitate, 2-lobed.

	Flower, lateral view.
© SRTurner

	Corolla and nectaries.
© SRTurner

Fruits - Ovoid capsules 15-25 mm long, longitudinally dehiscent.

	Infructescence portion.
© SRTurner

	Fruit and seeds.
© SRTurner

Flowering - May - July.

Habitat - Forests, glades, bases of bluffs, streambanks.

Origin - Native to the U.S.

Lookalikes - None when flowering. Vegetative rosettes can be mistaken for those of Cynoglossum or Veratrum.

Other info. - Here is a species which is easy to identify and impossible to miss, due to the tall, showy inflorescences. Even when vegetative the plant can be readily recognized by its distinctive, light green basal rosettes, which are distinguished from those of Cynoglossum by virtue of being glabrous. It is always a treat to encounter flowering specimens while strolling in the woods in late spring. The flowers are beautiful and interesting in detail, with large, fringed nectary glands on the petal surfaces. These attract a wild profusion of bumblebees, ants, and other insects. The plant's range in Missouri is mostly restricted to the southeastern quadrant of the state. Beyond Missouri it is mostly found in the U.S. Midwest.

The plant has a peculiar and interesting life cycle. Colonies of the large, leafy rosettes are common springtime sights in woodlands. A typical plant exists exclusively as a basal rosette for several years before finally sending up a flowering stalk, after which it dies. Bolting may be triggered partially by weather patterns, as regional mass flowering events have been observed. Studies on a related Western species, F. speciosa, have suggested that bolting is triggered by environmental cues occurring two years previously.

This species has been known as Swertia caroliniensis (Walter) Kuntze. Numerous additional members of the genus Frasera are found in western parts of the U.S.

Photographs taken at Crowley's Ridge Conservation Area, Stoddard County, MO, 3-29-2000, Valley View Glade Natural Area, Jefferson County, MO, 5-18-2010 and 5-24-2010, St. Joe State Park, St. Francois County, MO, 5-14-2012, S0haw Nature Reserve, Franklin County, MO, 6-05-2014, 7-17-2018, and 7-22-2020 (SRTurner); also at unrecorded site in Missouri, 3-29-2000 (JRAbbott).