Annual, taprooted, erect to suberect, unbranched or with ascending branches in canopy each with terminal inflorescence, erect, in range 15—30 cm tall; gynomonoecious; shoots with basal leaves and cauline leaves, pilose and short–pilose with hairs somewhat stiff and to 3 mm long.
Stems cylindric, to 2 mm diameter, tough.
Leaves helically alternate, simple and sessile, without stipules; blade oblanceolate to oblong or elliptic, 15—30 × 3.5—7 mm, tapered to long–tapered at base, in range entire, acute at tip, pinnately veined and 1 veined at base with midrib raised on lower surface, the longest hairs on margins.
Inflorescence solitary head, terminal on long peduncle, head radiate, ca. 25 mm across, in range of 11—17 pistillate ray flowers and 25—40 bisexual disc flowers, bracteate, short–pilose and pilose and with long–stalked glandular hairs, lacking resin glands; peduncle to 70 mm long, with greater number of stalked glandular hairs approaching involucre and sometimes having a bract subtending involucre narrowly lanceolate, 4.5 × 0. mm; involucre bell–shaped, ca. 6 mm across, of ca. 15 phyllaries in 3(—4) series, lanceolate, 4.5—7 × 0.8—1 mm, green with colorless margins, pilose and with long–stalked glandular hairs having greenish heads; receptacle somewhat convex, lacking bractlets (paleae) but each ovary surrounded by colorless, pillowy projections ca. 0.5 mm long.
Ray flower bilateral, 2.5—3 mm across; calyx (pappus) dimorphic, of ca. 15 scarious scales in 2 outer series and of ca. 20 inner bristles in 1 inner series, scales oblanceolate and flat, ca. 0.7 mm long, bristles stiff, in range 4—5 mm long, tawny; corolla unlobed; tube cylindric, ca. 3.5 × 0.3 mm, white; limb mostly 8.5—10 × 2.5—3 mm, bright yellow, lower surface of limb and adjacent tube with nonglandular and glandular short hairs; stamens absent; pistil 1; ovary inferior, obovoid compressed front–to–back, 1.8—2 × 0.7 mm, white, short–hairy, with green rim at top, 1–chambered with 1 ovule; style exserted, ± 4 mm long, 2–branched, below fork orangish, the stigmatic branches 0.5 mm long, orange–yellow aging red.
Disc flower radial, 1 mm across; calyx (pappus) dimorphic, of ca. 15 scarious scales in 2 outer series and of ca. 20 inner bristles in 1 inner series, scales oblanceolate and flat, ca. 0.7 mm long, bristles stiff, in range 4—5 mm long, tawny; corolla 5–lobed; tube cylindric, 1.6 × 0.35 mm, white; throat cylindric, ca. 2.5 mm long, lower portion nearly colorless with 5 yellow–orange veins, above midpoint yellow; lobes triangular, 0.6—0.7 mm long, yellow–orange to golden yellow; stamens 5, attached to top of corolla tube; filaments cylindric, ca. 0.8 mm long, pale yellow–orange; anthers included, basifixed, dithecal, 1.9—2.2 mm long with appendages, yellow–orange, longitudinally dehiscent; pollen pale yellow–orange; pistil 1; ovary inferior, obovoid compressed side–to–side, 1.8—2 × 0.7 mm, white, short–hairy, with green rim at top, 1–chambered with 1 ovule; style exserted, ± 6 mm long, 2–branched, below fork orangish, the stigmatic branches narrowly acuminate, 1.8—2 mm long, orange–yellow, most often tightly appressed, with short ascending hairs.
Fruits cypselae (achenes), dimorphic but with similar pappus, cypselae obovoid compressed, ca. 2.5 mm long, straw–colored to light brown, short–hairy, of ray flowers mostly with 10 raised ribs, of disc flowers smooth; pappus of widely spreading scarious scales ca. 0.7 mm long and tawny to rusty brown bristles to 5 mm long.
A. C. Gibson