Agalinis heterophylla (Nutt.) Small, prairie agalinis, prairie gerardia.
Stems 6–ridged, to 5 mm diameter, with 3 ridges descending from each leaf, tough, green stem flexible becoming woody, ridges with minute projections.
Leaves opposite decussate (subopposite), simple and sessile, without stipules; blades ± erect and often appressed, narrowly elliptic to oblong or narrowly oblanceolate, to 25 × 4.5 mm, at plant base 3–lobed or cut and to 45 × 8 mm, tapered at base, entire, acute at tip, appearing 1–veined with midrib sunken on upper surface and raised on lower surface, upper surface and margins minutely scabrous with upward–pointing teeth.
Inflorescence panicle of leafy, spikelike racemes, terminal, open, having lateral branchlets with 1—2 flowers per node, bracteate, glabrous; bract subtending lateral branch and bractlet subtending pedicel leaflike, appressed to flower and > calyx; pedicel 1—2.5 mm long, pale green, often wrinkled.
Flower bisexual, bilateral, ca. 25 mm across and long; calyx 5–lobed, in range to 8.5 mm long; tube ± funnel–shaped and 5–sided, 4—4.5 mm wide at orifice, low 5–ribbed with rib to each lobe, 10–veined, green; lobes mostly spreading, acute–triangular, 2—3.3 mm long, often purple or parts purplish; corolla 5–lobed, ± bell–shaped, in range ca. 25 mm long and wide, light purplish pink to dark pink (yellowish in bud); tube nearly cylindric, 2—2.4 mm diameter at base to 4 mm wide at top, veiny and white; throat with 5 dimples, loosely tomentose on outer surface, inner surface floor with 2 yellow strips and many purple–red spots; lobes 2 upper arching and 3 lower spreading, ± semicircular and overlapping, ca. 5.5 × 9 mm, short–tomentose and with ciliate margins; stamens 4, fused as 2 pairs at the same level, the longer pair on corolla floor, the shorter pair on upper side; filaments sigmoid, of longer stamens 9 mm long, of shorter stamens 7 mm long, white with purple spots, shorter filaments somewhat flattened and channeled, with some tomentose hairs above midpoint; anthers dorsifixed, dithecal with sacs separate, 3 mm long, cream–colored, sparsely hairy with crooked hairs, longitudinally dehiscent; pollen cream–colored; nectary disc surrounding base of ovary; pistil 1, ca. 15 mm long; ovary superior, ellipsoid, ca. 3 × 2 mm, glossy green, glabrous, 2–chambered with many ovules attached to center; style cylindric and nearly straight, white, with hooked to curved stigmatic tip, stigmatic lobes channeled, flattened top–to–bottom, short–papillate.
Fruit capsule, loculicidal, dehiscent by 2 valves, many–seeded, ellipsoid, ca. 9 × 5 mm before splitting, glossy brown, lacking stub of style at top; persistent calyx tube to midpoint of capsule.
Seed wedge–shaped to 5—6–sided polyhedral, 0.85—1.1 × 0.5—0.7 mm, brown, honeycombed.
A. C. Gibson