Croptilon divaricatum (Nutt.) Raf., slender scratchdaisy. Annual, taprooted, not rosetted, 1–stemmed at base, with spreading to ascending branch at each node, in range to 30—60 cm tall; gynomonoecious; shoots with only cauline leaves, mostly short–hirsute and in range not glandular.
Stems low–ridged, to 3 mm diameter, with 3 ridges descending from each leaf, tough, short–hirsute.
Leaves helically alternate, simple and sessile, without stipules; blade oblanceolate–linear to linear, in range 15—35 × 2.5—3.5 mm, often cupping axillary stem and half–sheathing at base, entire with toothlike enlarged hair base having some long hairs (especially near base) and with minute teeth on margins, acute with hard point at tip, 3–veined, at base with midrib pinnately veined having principal veins raised on lower surface.
Inflorescence head, canopy with many heads in ± open cymelike array, head radiate, 6—8 mm across, of 5—11 pistillate ray flowers and (9—)14—22 bisexual disc flowers, bracteate, short–hirsute on green tissues; bract subtending lateral branch sheathing and often clasping branchlet axis at base, linear, the lowest to 30+ × 3 mm decreasing upward, ciliate with enlarged bases of hairs base–to–tip mixed with minute teeth, principal veins raised on lower surface; branchlet axes widely spaced, with ridge descending from each bract.
Ray flower bilateral, 1.5—1.9 mm across; calyx (pappus) of ca. 30 capillary bristles, unequal, 2—3 mm long, white (= corolla tube); corolla minutely 3–toothed, with limb aging downward coiled; tube cylindric, ca. 3 × 0.2 mm, white at base to yellowish approaching limb, with several short hairs on outer side approaching limb; limb elliptic, ca. 3.5 × 1.7 mm, light yellow, finely 4–veined; stamens absent; pistil 1; ovary inferior, inversely conic, ca. 0.5 × 0.3 mm, colorless, densely covered with ascending straight short–hirsute hairs, 1–chambered with 1 ovule; style included, ca. 2.5 mm long, 2–branched, white below fork, the stigmatic branches ca. 0.5 mm long and yellowish.
Disc flower radial, bisexual, < 1 mm across; calyx (pappus) of ca. 30 capillary bristles, subequal, 3.2—4.2 mm long, white; corolla 5–lobed. ± 3 mm long; tube cylindric, 1 × 0.3 mm, white, glabrous; throat narrowly funnel–shaped, 0.7 mm diameter at orifice, colorless with 5 orangish stripes; lobes triangular, ±0.3 mm long, light yellow; stamens 5, attached to top of corolla tube, included; filaments ca. 0.8 mm long orangish, glabrous; anthers fused into cylinder surrounding style, 1.5 mm long including appendages 0.3 mm long, longitudinally dehiscent; pollen orangish; pistil 1; ovary inferior, inversely conic, ca. 0.5 × 0.3 mm, colorless, densely covered with ascending straight short–hirsute hairs, 1–chambered with 1 ovule; style included, ca. 4 mm long, 2–branched, orangish, the stigmatic branches ca. 0.8 mm long.
Fruit cypselae (achenes), narrowly top–shaped, 1.5—1.7 × 0.35 mm, brown, densely short–strigose with upward–pointing hairs; pappus bristles spreading, ca. 4 mm long, light brown.
A. C. Gibson