Spring-loving centaury

Centaurium namophilum Reveal, C. R. Broome & Beatley, Bull. Torrey Bot. Club 100: 353, fig. 1. 1974

Herbs annual, (5–)15–45 cm. Stems often 1, occasionally 2–5(–10), branching ± throughout. Leaves cauline; blade narrowly lanceolate (proximal) to linear or filiform (distal or all), 10–50 × 1–5 mm, apex subacute to acute. Inflorescences thyrses of largely dichasial cymules; central pedicels in divisions of proximal cymules 5–20 mm, other pedicels 0–9 mm. Flowers generally 5-merous; calyx 6–9 mm; corolla 13–18 mm, lobes lanceolate, 5–8 mm, apex acute to acuminate except for blunt extreme tip; stigma 1, shallowly 2-lobed, lobes fan-shaped. Seeds black. 2n = 34.

Flowering spring–fall. Wet meadows near springs and streams; of conservation concern; 600–1400 m; Calif., Nev.

Zeltnera namophila has been reported from Utah, but documentation has not been found in studies for this flora.

Although plants of Zeltnera namophila sometimes have been identified as Z. exaltata, these species are usually distinct in morphology. The larger plants of Z. exaltata are often several-stemmed at the base, with strongly ascending branches. Branching is largely dichasial proximally, monochasial distally. Most of the pedicels (distal to all bracts) are longer than the flowers. Zeltnera namophila, regardless of plant size, is often although not invariably single-stemmed at the base. The primary stem or stems of well-developed plants of Z. namophila usually maintain a distinct central axis for much of their height, the inflorescence thus being a paniclelike thyrse. The proximal primary branches spread relatively widely, often at more than 45°. The pedicels are generally shorter than the flowers, although solitary flowers borne above small bracts on slender branches may appear to be long-pedicellate. All leaves of Z. namophila are linear or nearly so, whereas in Z. exaltata the basal leaves, which are often persistent, and the cauline leaves to mid stem are usually oblong-elliptic to lanceolate. The flowers of Z. namophila are generally five-merous, whereas those of Z. exaltata are four-merous, and the fresh corollas of Z. namophila are deeper pink. The corolla tubes of Z. namophila are 6–9 mm, and the lobes are 5–7 mm, distinctly more than half as long as the tube; the corolla tubes of Z. exaltata are 7–15 mm, and the lobes are 3–5 mm, about half as long as the tube or shorter.