Jepson 2012, Kearney and Peebles 1969, Allred and Ivey 2012, McDougall 1973, Heil et al. 2013

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Annual to biennial herbs, 20-40 cm tall; stems weakly spreading, not much branched. Leaves: Opposite along the stem, and also with basal leaves often forming a rosette; blades lanceolate to oblong, 2-7 cm long. Flowers: Bright pink and showy, with few flowers borne mostly erect in open cymes; corolla 14-25 mm long, salverform (a slender tube with petals abuptly spreading and flat), with 5 lanceolate lobes (petals) on top, these about 1 cm long with pointed tips; calyx lobes appressed to the corolla. Fruits: Capsules with 2 valves; containing many tiny seeds. Ecology: Found in open, damp places, especially on streambanks, at the lower and middle elevations; flowers April-May. Distribution: s CA, AZ, NM, s TX; south to c MEX. Notes: This pretty gentain with its tubular pink-purple flowers topped with 5 perfectly ovate petals with yellow throats grows in wetlands along streams. It is distinguished by the distinct showy flowers; seed pods filled with tiny dark seeds; wetland habitat; opposite leaves along the stem; and many basal leaves. In most regional floras the taxon is considered synonymous with Centaurium calycosum or the more recent name Zeltnera calycosa. However, Allred and Ivey treat is as a distinct taxon, distinguished by being taller than 20 cm with weak, mostly unbranched stems. According to Allred, Z. calycosa has a single stem, 5-20 cm tall, which is much-branched above the base, and no basal leaves. Kearney and Peebles, on the other hand, note that there is much variation within Centaurium calycosum, but there seems to be no satisfactory basis for the distinction of varieties. Ethnobotany: Unknown. Etymology: Zeltnera is named after Louis Zeltner (1938- ) and Nicole Zeltner (1934- ), Swiss botanists and biosystematists; arizonica means of or from Arizona. Synonyms: Centaurium arizonicum, Centaurium calycosum var. arizonicum, Erythraea arizonica, Erythraea calycosa var. arizonica Editor: LCrumbacher 2012, FSCoburn 2015, AHazelton 2017