After yesterday’s presentation on the “Four Corners of Oregon” to the Friends of the UBC Botanical Garden, it occurred to me that I have a few nice photographs of members of the gentian family. So, I’m going to follow one series with another, this time on the Gentianaceae.
I believe today’s species is the Oregon native Monterey centaury (Zeltnera muehlenbergii) and not the close-in-appearance, and introduced-to-North America, common centaury (Centaurium erythraea). One of the key identifying characteristics between the two species is whether or not the individual flowers always have two bracts at the base and are sessile (emerging directly from the stem) or whether some flowers are pedicellate (having pedicels, or short stalks connecting the base of the flower to the stem). I have other, poorer photographs that seem to show some pedicellate flowers, so my conclusion is Zeltnera muehlenbergii as opposed to Centaurium erythraea (but I welcome any discussion on the matter). Another point in favour of it being Zeltnera muehlenbergii is that it was growing at the edge of a wet meadow and pond, whereas Centaurium erythraea is typically a species of dry to mesic conditions (though it will also grow in wet places).
Most references on the species Zeltnera muehlenbergii will use a synonym, Centaurium muehlenbergii. The name change to Zeltnera occurred in 2004 with Guilhem Mansion’s Taxon paper on “A New Classification of the Polyphyletic Genus Centaurium Hill (Chironiinae, Gentianaceae): Description of the New World Endemic Zeltnera, and Reinstatement of Gyrandra Griseb. and Schenkia Griseb.“. With this taxonomic treatment, the genus Centaurium changed from about 30 species occupying mainly north temperate regions with one species extending to Chile and another to Australia, to a genus comprised of 20 Eurasian species. The species of Centaurium found in the western Americas were moved into the newly-erected genus, Zeltnera.
Monterey centaury is native to western North America from British Columbia to California. Had I found this species in British Columbia, it would have been a bit of a coup as it is a red-listed species (i.e., threatened or endangered) found only in a few locations. However, along the coast of southern Oregon, it is fairly common.
If I recall correctly, it had a sweet fragrance.