Glandularia bipinnatifida (Nutt.) Nutt., dakota vervain, prairie verbena. Annual or perennial herb, taprooted and often fibrous–rooted on prostrate stems, several–stemmed at base, decumbent or procumbent to ascending, in range 10—40 cm tall, spreading to 40 cm from taproot; shoots never strongly 2–dimensional (plagiotrophic) but horizontal, spreading shoots often with leaves oriented to upper side, not tufted, short–hirsute, short–strigose, and hirsute, sometimes somewhat hispid, with some inconspicuous glandular hairs; adventitious roots at nodes of basal stems and horizontal stems touching the ground.
Stems 4–sided and ± 4–angled, to 4.5 mm diameter, often with reddish purplish red angles and sometimes midveins, internodes to 55 mm long and facing sun sometimes purplish red, hairs mostly spreading.
Leaves opposite decussate, deeply, mostly symmetrically 2–pinnately dissected (larger leaves) to 1–pinnately dissected (smaller leaves), petiolate with pair connected by low ledges across node, without stipules; petiole channeled, indistinct from blade, to 25 × 1—1.5 mm, 1–veined, the vein white, upper side glabrous, lower side and margins hirsute, commonly with some glandular hairs on lower side; blade ovate to broadly ovate or broadly triangular in outline, < 15—55 × < 15—80 mm, primary segments of larger leaves mostly opposite to subopposite and ± equal, the lower ones to 35 mm long, principal axis mostly < 3(—7) mm wide, channeled with halves somewhat unequal, segments oblanceolate to oblong or fusiform and ultimate segments like acute lobes or teeth, < 8 mm long, pinnately veined with principal veins sunken on upper surface and raised on lower surface, upper surface sparsely short–strigose to strigose with upward–pointing hairs, lower surface hirsute along margins and veins.
Inflorescence spike, terminal, densely many–flowered, at anthesis appearing flat–topped, axis elongating in fruit, flowers ± alternate to subopposite decussate, bracteate, hirsute; peduncle to 10 mm long; rachis at anthesis with conspicuous purplish red stripes, increasing in fruit by forming internodes, internodes ± cylindric, 2.5—3(—8) mm long, hirsute and pustulate short–hirsute with stalked glandular hairs; bractlet subtending flower awl–shaped to lanceolate–linear, slightly > calyx, green with midvein and margins colorless, upper surface glabrous, lower surface hirsute, persistent and fused to receptacle.
Flower bisexual, slightly bilateral, 8—12 mm across with oblique limb, ca. 11 mm long, strongly and sweetly fragrant like lilac (Syringa); calyx 5–lobed (toothed); tube ± pleated and 5–ribbed, 6.5—8 × 1.1—1.7 mm, expanding slightly above midpoint, ribs green alternating with membranous or translucent–purple strips (furrows), with several glands like those on bractlet; lobes unequal, fingerlike extensions of ribs, the shortest lobe on upper side to 0.7 mm long, lateral 2 lobes ca. 1.5 mm long, the longest 2 on lower side 3—3.3 mm long, with stiff hairs on margins; corolla slightly 2–lipped, 5–lobed, narrowly trumpet–shaped (salverform), > calyx, generally reddish purple (magenta) or deep purple to blue–purple (all–white cultivars); tube 6.5—10 × 0.7—1 mm, not expanded around ovary, whitish but pinkish approaching top, internally glabrous to midpoint and hairy above midpoint, the hairs varying from upward–pointing to downward–pointing or spreading, fading to white at base; throat slightly expanding from tube and mostly above calyx, lower throat 2.5—4 × 1.5 mm, pale violet, upper throat funnel–shaped, 3 mm long, violet, internally white–hairy with downward–pointing hairs on lower part opposite lower anthers to upward–pointing hairs on upper part; upper lip 2–lobed, lobes oblong, ca. 3 × 1.3 mm, rounded at tip (not notched), lower lip 3–lobed, 4.5—5 × 2.5—4.5 mm, lateral lobes widely spreading, ca. 2.5 × 1.8 mm and shallowly notched, central lobe wider and conspicuously notched, ca. 3 × 2.3 mm, lips brilliantly colored but paler on lower surface, upper surface with domed cells, short–hirsute; stamens 4, all fertile, pairs fused to corolla at different levels, 2 stamens arising at top of corolla throat and barely visible and 2 stamens at base of throat and not visible, upper stamens 1—1.5 mm long and lower stamens ± 1 mm long; filaments ± 0.7 mm long (upper stamens) and 0.5 mm long (lower stamens), yellowish green, anthers basifixed, dithecal, ± heart–shaped, having equal sacs but obliquely positioned or unequal and having a subterminal appendage (upper stamens) and equal or subequal sacs lacking appendage (lower stamens), 0.7—1 mm long, yellowish green to light green, longitudinally and inwardly dehiscent, the appendage = a fingerlike extension of connective ± 0.5 mm long, purple and resembling cluster of grapes (colliculate); pollen whitish or colorless to pale yellow; nectary disc below ovary, 0.25 mm long, green; pistil 1; ovary superior, 4–lobed, ± 1 mm × 0.6 mm, 4–chambered, each chamber with 1 ovule; style nearly = corolla tube–throat (typically 9—10 mm long), light green, compressed side–to–side approaching 2–forked tip, light green, with stigma in crotch, the longer fork surpassing stigma and slightly exserted from corolla throat hairs, ± conic, arched outward and compressed side–to–side, the shorter fork triangular and < stigma; stigma at same level as upper anthers, ± spheroid, 0.3—0.35 mm, dark green at base to pale green above, papillate.
Fruits schizocarp (microbasarium), of 4 dry, 1–seeded mericarps (nutlets), nutlets oblong–linear, 3—4 × 0.7—1 mm, the widest and slightly flaring at base, brown on outer faces, angled with fine, warty growths (muricate) on inner faces, longitudinally 4–veined on outer face but with cross veins and appearing pitted above midpoint; persistent calyx with several purple stripes before drying.
A. C. Gibson