Rough-stemmed centaury

Centaurium beyrichii (Torrey & A. Gray) B. L. Robinson var. glanduliferum Correll, Wrightia 4: 76. 1968 (as Centaureum); C. glanduliferum (Correll) B. L. Turner

Herbs annual, 5–20 cm. Stems 1–30+ from crown, branching throughout, densely papillose-puberulent. Leaves: basal present or ± withered at flow­ering, similar to cauline; blade linear, 10–40 × 1–3 mm, apex obtuse to acute, abaxially papillose-puberulent along midvein. Inflorescences dense, much-branched, dichasial cymes; pedicels 2–10 mm. Flowers 5-merous; calyx 5–9 mm, papillose-puberulent along midveins; corolla 13–17 mm, lobes narrowly oblong-lanceolate, 5–7 mm, apex acute; stigmas 2, fan-shaped. Seeds nearly black. 2n = 40.

Flowering summer–fall. Roadsides, other open, often rocky sites, in calcareous soils; 800–1100 m; Tex.

Zeltnera glandulifera is endemic to Brewster, Pecos, and Terrell counties in trans-Pecos Texas. Its range is about 200 km west of that of Z. beyrichii.

Zeltnera glandulifera is similar to Z. maryanniana, from which its range is wholly southeast. The species differs most distinctly in that its stems, leaf and calyx midveins, and especially its pedicels and inflorescence branches are copiously papillose-puberulent, mostly in lines.