Palafoxia callosa (Nutt.) Torrey & A. Gray, small palafoxia. Annual, taprooted, not rosetted, 1–stemmed at base, with ascended branches from successive nodes, 18—70 cm tall; shoots with only cauline leaves, foliage mildly scabrous, short–strigose with upward–arching hairs.
Stems cylindric, to 4 mm diameter, tough, somewhat zigzagged, lacking stalked glands; major axis developing periderm light brown in splits alternating with patches of short–strigose hairs.
Leaves opposite decussate (lower leaves and the lowest leaves of new shoots) and helically alternate (canopy), simple, petiolate, without stipules; petiole channeled, to 7 mm long; blade linear, 13—50 × 1—4 mm , tapered at base, entire, acuminate with callous point at tip, 1–veined with midrib sunken on upper surface and raised on lower surface.
Inflorescence head, terminal and axillary, in open, cymelike array of heads, ± flat–topped, of several—20+ heads, head showy, discoid, 13—17 mm across, 10—15–flowered, bracteate, with glandular hairs; bract subtending peduncle appressed, awl–shaped, ca. 3 mm log, short–strigose; peduncle slender, 10—20 mm long, with conspicuous, radiating, stalked glandular hairs and short–arching hairs; involucre funnel–shaped or narrowly top–shaped to cup–shaped, 5.5—6 × 3—4 mm, purplish red, with sparse nonglandular hairs, phyllaries ca. 8, outer phyllaries lanceolate to inner phyllaries elliptic–oblong to oblanceolate–linear, 3.7—5.5 mm long, green to red–purple above midpoint with white at tip, with narrow membranous margins, short–strigose with upward–arching hairs; receptacle with a low, lacking bractlets (paleae) subtending flowers, green rim surrounding each ovary of the central flowers, hollow beneath receptacle.
Flower bisexual, radial, ca. 7 mm across; calyx (pappus) in range 8—10 in 1—2 series, free or some fused at base, ascending, obovate to elliptic, at anthesis < 1 mm long, colorless and scarious with thick midvein, jagged on margin above midpoint; corolla 5–lobed, in range 6—6.8 mm long; tube cylindric, ca. 1.8 × 0.3 mm, colorless at base to rose–pink at top, with some short hairs and glandular hairs; throat cup–shaped, 0.6—0.7 mm long, rose–pink; lobes lanceolate, 3.8—4.3 mm long, rose–pink; stamens 5, fused at top of corolla tube; filaments slender, ca. 2.2 mm long, pale pink; anthers fused into cylinder surrounding style, basifixed, dithecal, ± 2.5 mm long, deep purple–red, longitudinally dehiscent; pollen white; pistil 1; ovary inferior, wedge–shaped 4(—5)–sided, ca. 1.2 mm long, whitish; nectary disc surrounding base of style, 5–sided, 0.25 mm long, white, producing copious nectar; style partially exserted 1 mm above anthers, 7—8 mm long, pink, 2–branched above midpoint, the branches initially erect and appressed aging coiled, conspicuously papillate with dark pink tips.
Fruits cypselae (achenes), wedge–shaped 4(—5)–sided, 3.5—4 × 0.7—1 mm, black (mottled brown), with conspicuous angles, truncate at top, short–strigose with upward–pointing hairs; pappus scales in range 8—10, persistent, free or some fused at base, scarious with thick midvein, unequal, obovate to elliptic, 0.3—1.6 mm long, some with lateral lobe, scarious with tannish midvein (immature green), jagged on margin.
A. C. Gibson