Flora of North America species comparison

Varieties 2 (2 in the flora).

The two varieties of Gentiana newberryi intergrade extensively. The most distinctive form of var. newberryi, with relatively tall stems and medium to deep blue corollas, occurs in the northern part of the range of the species, from the Klamath and White mountains of California north into Oregon. Plants most clearly referable to var. tiogana prevail in the southern part of the range of the species, from Butte County south to Inyo and Tulare counties, California. In the central part of the range of the species, plant size and corolla color are less consistently correlated, with occasional plants combining low stature with deep blue corollas or tall stems with predominantly white or pale blue corollas. In that part of the range, corolla color may be highly variable within a single population.

The leaves of Gentiana newberryi are thick-textured and distinctively concave, usually spoon-shaped, when fresh. Narrower leaves sometimes occur in var. tiogana, but many plants of that variety have widely spatulate leaves like those of var. newberryi.

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

Genera ca. 100, species ca. 1800 (18 genera, 112 species in the flora).

In the tribal classification by L. Struwe et al. (2002), genera 1–7 in this flora are in tribe Chironieae Dumortier, subtribe Chironiinae G. Don. Species of Chironieae generally lack nectaries, although Sabatia reportedly has indistinct nectaries at the base of the ovary. Genera 8–17 are in tribe Gentianeae Dumortier. Gentiana, in which the nectaries are on the gynophore, is in subtribe Gentianinae G. Don; the remaining genera of the Gentianeae in the flora area, all of which have epipetalous nectaries, are in subtribe Swertiinae Grisebach. Voyria constitutes the monogeneric tribe Voyrieae Gilg, in which the nectaries (when present) are on the ovary or the gynophore.

Pedicel lengths given here refer to the true pedicels, between the most distal pair of bracts or bractlets and the calyx. In some genera, notably Centaurium, Sabatia, and Zeltnera, a flower terminating the ultimate branch of an inflorescence, directly subtended by bractlets, although sessile by this definition, may appear pedicellate. Corolla lengths as given are from the receptacle to the apices of the lobes (or plicae in Gentiana andrewsii).

The Gentianaceae include many species esteemed in ornamental horticulture. In addition to those noted under the respective genera, the more important species in North American horticulture include Exacum affine Balfour f. ex Regel, Persian-violet, native to the island of Socotra, Yemen, which is widely grown as a florists’ pot plant.

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