Centemopsis kirkii Schinz

Annual herb (or probably short-lived perennial in more native habitats), erect, 15–100 cm.. Stem wiry, strongly striate with pale ridges, smooth and glabrous except for tufts of multicellular whitish hairs about the nodes to strongly scabrid and moderately pilose, much branched from near the base upwards (simple in poorly grown forms), the branches ascending with sterile axillary short shoots.. Leaves linear-filiform to lanceolate-elliptic, 1.2–8.5 cm. × 0.75–16 mm., surfaces glabrous to ± finely hairy, ± scabrid along the incrassate margins and lower surface of the midrib, gradually narrowed above to a mucronate apex, attenuate and indistinctly petiolate below.. Inflorescence mauve-pink to crimson or purplish red (becoming stramineous in dried material), spiciform or reduced and capitate, 1.5–3.5 × 1–1.3 cm. in flower, rounded or conical at the tip, where more aristate bracteoles frequently give it a bristly appearance; in fruit elongating to as much as 13 cm.; axis white lanate, deeply sulcate, after the fall of the fruiting perianth often finally honeycombed with pits formed by the widening of the grooves above each flower scar, and densely clad with the persistent bracts.. Bracts lanceolate to ovate-lanceolate, 2.5–5 mm., membranous with a dark shortly excurrent midrib, glabrous to ciliate.. Bracteoles deltoid-ovate, 2–4 mm., acute to truncate or in the uppermost flowers sometimes even incised above, membranous with a distinctly excurrent midrib, glabrous to ciliate.. Flowers 1–2 in the axils of the bracts.. Tepals oblong to subpanduriform, 3.5–6 mm.; outer 2 at anthesis with a deltoid-ovate, not or narrowly hyaline margined, opaque, glabrous to sparingly floccose strongly 3-nerved base, usually ± constricted above, the apical half being lanceolate, increasingly widely hyaline-margined upwards with the margin incurved and with the midrib shortly excurrent; inner 3 increasingly more delicate, narrower and more obviously constricted centrally, distinctly 3-nerved below with the hyaline margin descending much nearer the base; all tepals but (especially the outer) indurate and prominently 3-ribbed at the base in fruit (deeply sulcate between the ribs), giving the inflorescence a frequently spiky appearance.. Filaments very slender, 2–3.5 mm.; pseudo-staminodes oblong or spathulate, 1–1.5 mm., denticulate to fimbriate around the apex.. Ovary ovoid, glabrous and hyaline below, firm above, pilose centrally and more thinly so above.. Style 1.5–3.5 mm., glabrous, slightly asymmetrically placed on the ripe capsule.. Capsule 1.5–2 mm., formed as the ovary but somewhat compressed.. Seed compressed-ovoid, brown, ± 1.25–1.75 mm., shining, minutely reticulate.. Fig. 11/1–3.