Flora of North America species comparison

The name Gentiana alba Muhlenberg has often been applied to this species. Uncertainty had long persisted, first as to whether the name G. alba was validly published by G. H. E. Muhlenberg in 1813, then, after that publication had been deemed invalid, whether it was validated by T. Nuttall in 1818. A group of nomenclatural authorities considered this issue on behalf of this flora and concluded that neither of those publications of the name G. alba had been valid, and that G. flavida A. Gray was the earliest validly published name for this species (K. N. Gandhi, pers. comm.).

Outlying eastern populations of Gentiana flavida in North Carolina, Pennsylvania, and West Virginia are no longer extant, and the continued existence of other peripheral populations in isolated prairie remnants is precarious. Reports from Manitoba have been based on misidentified G. rubricaulis. A report from Maryland was based on the misreading of a label of a specimen actually from Indiana (studies for this flora).

In contrast to those of the other species of Gentiana in the flora area, with the exceptions of G. clausa and G. latidens, the calyx lobes of G. flavida spread widely, with keels like shelf brackets decurrent on the tube.

Morphological variation in Gentiana flavida should be given further study. According to J. T. Curtis (1959), plants of this species from the northern part of its range, as seen in the field, appear distinctly different in inflorescence form from plants native farther south.

In the tall-grass prairies, Gentiana flavida hybridizes with G. andrewsii, producing G. × pallidocyanea J. S. Pringle, and G. puberulenta, producing G. × curtisii J. S. Pringle. Reports of G. flavida with the corollas distally lilac have been based on plants derived from such hybridization, probably through backcrossing.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Gentiana pennelliana is endemic to Bay, Calhoun, Franklin, Gadsden, Gulf, Leon, Liberty, Wakulla, and Walton counties in northern Florida. It usually grows in plant communities in which wiregrass, Aristida stricta, is a prominent component, hence the common name.

Gentiana pennelliana differs further from G. autumnalis in its longer, more gradually flaring corolla tube; the division of the lateral veins of the corolla near the base, so that each petal has five primary veins rather than three as in G. autumnalis and the other Gentiana species in the flora area; and stamens 7–12 mm above their insertion on the corolla tube, as contrasted with 13–30 mm in G. autumnalis.

(Discussion copyrighted by Flora of North America; reprinted with permission.)