Grindelia texana Scheele, texas gumweed. Annual, taprooted, not rosetted, 1–stemmed at base, with ascending branches in canopy, erect to ascending, in range 25—95 cm tall, shoot to 105 cm long; shoots with petiolate basal leaves and mostly sessile cauline leaves, basal leaves absent at flowering, foliage on plant not resinous, aromatic when crushed, vegetative shoots glabrous and not obviously gland–dotted.
Stems 3–ridged, to 3 mm diameter, with 2 fine ridges descending from each leaf, glabrous, lower stems woody.
Leaves helically alternate, simple and sessile, mostly not clasping at base, without stipules; blade oblong or oblong–obovate to deltate or ovate, 10—35 × 4—11 mm, base short–fused to base with free portion truncate or broadly tapered, regularly serrate with pointed teeth and minutely scrabrous with short, appressed hairs on margin, teeth midblade 3—4 per cm with to 10 per edge, acute to obtuse at tip, pinnately veined with midrib raised on lower surface.
Inflorescence heads in leafy, cymelike array of 1—3(—7) heads, terminal, head radiate, 16—32 mm across, with ± 30 pistillate ray flowers and many bisexual disc flowers, bracteate, glabrous; peduncle short, with several small leaflike bract later subtending a head; involucre hemispheroid to subspheroid, 7—17 mm across (with ascending and spreading phyllaries 12—23 mm across), green and conspicuously resinous, phyllaries mostly 100+ in 6—9+ series, free portions subequal, fleshy, mostly hemicylindric to pointed tip, 4—6 × 1 mm, mostly incurved with reddish point, of inner 2 series flat and acute narrowly lanceolate–linear often lacking reddish point; receptacle low–convex, lacking bractlets (paleae), pitted and crownlike surrounding each disc ovary tightly nested by crown, crown to 0.4 mm tall with blunt teeth on margins, white, glabrous.
Ray flower bilateral, 2.5—2.8 mm across; calyx (pappus) of 2 opposite, smooth, capillary “bristles,” 5—6.5 mm long, somewhat club–shaped at tip, easily detached; corolla unlobed; tube strongly 4—5–sided, 3—4 × 0.5—0.7 mm, white, thick–walled at base somewhat bulging above ovary, glabrous; limb narrowly elliptic to oblong, 7—10 × 1.5—2 mm, bright yellow, obtuse at tip, glabrous; stamens absent; pistil 1; ovary inferior, 4–sided wedge–shaped, 0.7—1 mm long, translucent white, glabrous, 1–chambered with 1 ovule; style exserted 2 mm, ca. 5.5 mm long, 2–branched, pale yellow at base, the stigmatic branches ca. 1.8 mm long, golden yellow.
Disc flower radial, 1 mm across, ca. 7 mm long; calyx (pappus) of 2 opposite, smooth, capillary “bristles,” 5—6.5 mm long, somewhat club–shaped at tip, club–shaped portion often exserted above corolla, easily detached; corolla 5–lobed; tube cylindric, ca. 1 × 0.65—0.7 mm, white; throat cylindric, to 1 mm diameter, colorless; lobes erect, triangular, 0.3—0.7 mm long, golden yellow; stamens 5, attached at top of corolla tube; filaments 1.5—2 mm long, yellowish; anthers basifixed, dithecal, 3 mm long including appendage 0.4 mm long, golden yellow, the appendages exserted, blunt–triangular, longitudinally dehiscent; pollen golden yellow; pistil 1; ovary inferior, ± 4–sided wedge–shaped, 0.7—1 × 0.7—1 × 0.35 mm, translucent, glabrous, 1–chambered with 1 ovule; nectary disc surrounding base of style, ca. 0.4 mm long, colorless; style 5—5.5 mm long, 2–branched, whitish at base, pale yellow approaching fork, the stigmatic branches appressed, ca. 1.3 mm long, golden yellow, papillate–hairy.
Fruits cypselae (achenes) polymorphic, of ray flowers ± 3–sided, 2.7—4 × 1.5—2 × 1.5—2 mm, brownish, faces ± smooth or with low ridges, resin–covered, of outer disc flowers oblong to rectangular strongly flattened, 3—5 × 1.5—2 mm, tan, finely parallel–ribbed on faces, with rim at top higher on 1 edge, of inner disc flowers somewhat top–shaped compressed side–to–side (obpyramidal), 2.7—4 × 1.2—1.5 mm, whitish to straw–colored, with 15+ low ribs on each face.
A. C. Gibson