English: Arizona centaury; Shortflower centaury; Rosita; Buckley centaury.
Genus: 25 species.
TaxonomyZeltnera as a genus was erected in 2004 when the polyphyletic genus Centaurium was split into four clades. Centaurium got limited to the Eurasian species. Gyrandra contains the Mexican species. The Mediterranean and Australian plants are in genus Schenkia. Zeltnera was split off from Centaurium for the North American centauries.
Zeltnera can be subdivided into three groups, a division supported by DNA evidence and geography: Californian group, Texan group and Mexican group.
BotanyAnnual, biennial, or short-lived perennial herbs.
Root: taproot or fibrous root systems.
Stem: one or more branching stems; often ridged; sometimes winged.
Leaves: around the lower stem or arranged along the length of the stem; linear to lance-shaped to oval; green or yellowish.
Inflorescence: variable in arrangement.
Flower: tubular throat that opens into a flat corolla with four or five lobes; pink or white, the throat is usually paler, white or yellowish, or patterned with green.
Fruit: small capsule, with up 700 minute seeds.
DDCentaurium species differ mostly in the morphology of the style, stigma and the fruit capsule.