Zeltnera texense (Griseb.) G. Mans., lady bird centaury. Annual, slender–taprooted, not rosetted, 1–stemmed at base, with a branched, terminal inflorescence from below midplant, erect, 7—20 cm tall; shoots with only cauline leaves, glabrous.

Stems

Stems 4–ridged and 4–sided, 2 faces somewhat convex below leaves, 2 faces flat, with ridges descending from ledge (not leaf), internodes to 20 mm long.

Leaves

Leaves opposite decussate, simple, sessile with pair forming ledges across node, without stipules; blade linear or linear–lanceolate to narrowly elliptic or obovate, < 6—25(—33) × 1—4(—7) mm, entire, acute at tip, 1–veined.

Inflorescence

Inflorescence compound cyme, terminal and sometimes axillary, open, many–flowered, bracteate, glabrous; bracts subtending cymes in pairs, leaflike, decreasing upward; peduncle erect (suberect if axillary), stemlike; bractlet subtending pedicel elliptic–linear, 4—6 × 0.6—0.7 mm; pedicel suberect to ascending, stemlike, 4–ridged and 4–sided, at anthesis < 4—6 mm long not increasing in fruit.

Flower

Flower bisexual, radial, in range 7.5—13 mm across; calyx 4—6–lobed, 7—9 × 1.3—1.5 mm, green, glabrous; tube ca. 1 mm long; lobes subequal, linear, keeled; corolla 4—6–lobed, 11—14 mm long; tube + throat exserted < 1 mm above calyx (constriction), white, tube ribbed and obvious in fruit (ca. 20–ribbed); throat short funnel–shaped, 1.2—1.4 mm across at orifice; lobes widely spreading, ± elliptic to obovate, 3.8—6 × 1—2.6 mm, rose, pink, to pale pink (white), paler on lower surface, often minutely notched at tip or remotely toothed; stamens 4—6, fused to base of corolla throat and decurrent inside upper corolla tube (yellowish), alternate with corolla lobes, exserted; filaments straight, 2.1—2.6 mm long, white (yellowish at base), glabrous; anthers basifixed, dithecal, 2—2.2 mm long, light yellow, longitudinally dehiscent; pollen light yellow; pistil 1, 13—14 mm long, exserted; ovary superior, cylindric, ca. 7.5 × 0.8—0.9 mm, glossy solid green. 1–chambered and longitudinally grooved over each placenta, the 2 placenta intruding with numerous ovules; style ca. 4.5 mm long (including stigma lobes), 2(—3)–branched, 2–channeled approaching stigma, white, the stigmatic branches oval to roundish, 0.7 mm long, cream–colored, papillate.

Fruit

Fruit capsule, septicidal, dehiscent by 2 valves, many–seeded, narrowly fusiform, 8—9 mm long, golden brown, dehiscing below midpoint with tips of valves spreading.

Seed

Seed ovoid, 0.3—0.4 mm long, charcoal, conspicuously netlike and ridged.

A. C. Gibson