Physaria gordonii (A. Gray) O’Kane & Al–Shehbaz, popweed, gordon’s bladderpod, beadpop. Annual, taprooted, rosetted, 1—several–stemmed at base, erect (1–stemmed) to ascending or decumbent, in range < 30 cm tall; shoots with basal leaves and cauline leaves, green surface with appressed stellate hairs seastarlike with (4—)6—8 arms, the arms arising from the center (not fused) and center domelike, arms with minute projections (tuberculate).
Stems ± cylindric, to 1.5 mm diameter, tough and wiry, internodes < leaves, green.
Leaves helically alternate, simple, petiolate, without stipules; petiole ± hemicylindric, 11—15 mm long (basal leaves) and = blade, decreasing upward, with scattered appressed stellate hairs; blade obovate to elliptic, 11—24 × 4—8.5 mm, tapered to long–tapered at base (not clasping), entire to low–dentate or having remote teeth on margins, acute at tip, pinnately veined with midrib sunken on upper surface and principal veins ± raised on lower surface, stellate hairs uniformly distributed.
Inflorescence raceme, terminal, 15+–flowered, = upper 1/2 of plant, without bracts, with appressed stellate hairs on exposed green tissues; peduncle stemlike, cylindric, to 15 mm long; rachis cylindric, in fruit < 120 mm long; pedicel cylindric, at anthesis 8—10 × 0.5 mm and not hooked aging 2× and sigmoid with hook upward just below fruit.
Flower bisexual, ± radial, 10—12 mm across; buds nodding; sepals 4, ascending, oblanceolate or oblong to narrowly elliptic, 4.5—5.5 × 1.1—1.4 mm, faintly 3–veined at base, minutely hoodlike at tip, narrowly membranous on margins (inner pair), with appressed stellate hairs outer (lower) surface and glabrous inner (upper) surface; petals 4, 7—7.5 × 4—4.4 mm, ± clawed (poorly defined), claw 1 mm long, colorless at base, limb oblanceolate somewhat cupped upward, bright yellow, rounded at tip, pinnately veined; stamens 6, free, dimorphic, with outer 2 short and inner 4 longer; filaments ascending, 4—5 mm long in each flower, yellow but white at base; anthers dorsifixed, dithecal, 1.8—2.1 mm long, yellow, longitudinally dehiscent; pollen pale yellow; nectaries 4 in 2 pairs at bases of short stamens, green; pistil 1, subsessile with minute stalk (stipe) at anthesis < 0.15 mm long; ovary superior, ellipsoid, ca. 2 × 1 mm, glabrous, 2–chambered, each chamber with several ovules; style cylindric, ca. 4 mm long, greenish; stigma capitate, terminal, at level of the long stamens, spheroid, 0.4 mm, green.
Fruit siliqua (silicle), dehiscent by 2 valves parallel to septum, to 10–seeded, subspheroid, ca. 5.5 × 4 mm, somewhat inflated, septum complete and slightly raised on surface, glabrous; pedicel distinctly sigmoid with bend upward beneath fruit, 16—20 mm long; stipe beneath siliqua < 0.5 mm long.
Seed lens–shaped, ca. 1.2 × 0.8 mm, brown, lacking wing, smooth; cotyledons acumbent.
A. C. Gibson