Baptisia leucophaea Nutt., . Baptisia leucophaea — WILD INDIGO, PLAINS WILD INDIGO [Fabaceae]g Perennial herb, from woody caudex, several–stemmed at base, unequally forked at many nodes, branched at ground level in late summer, ascending to spreading, in range to 45 cm tall; shoots with only cauline leaves, foliage tough, somewhat glaucous.
Stems ± cylindric, initially 1 mm diameter, at base with periderm to 5 mm diameter, glabrous.
Leaves helically alternate, palmately 3–foliolate, short–petiolate lacking pulvinus, with stipules; stipules 2, leaflike (photosynthetic), firmly and broadly attached to well–developed ledge on stem, sessile, somewhat asymmetric lanceolate to arrow–shaped, (10—)15—52 × 7—20 mm (smaller on the diminutive earliest leaf of each shoot), entire, acuminate (acute) at tip, pinnately veined with midrib not raised and having a fine network of minor veins, initially villous aging ciliate on margins, persistent; petiole broadly channeled, < 2—10 mm long, glabrous; blades of leaflets obovate with lateral leaflets slightly asymmetric, < 35—70 × < 15—35 mm, tapered at base, entire, obtuse (acute) at tip, pinnately veined with midrib raised on lower surface, villous aging glabrescent.
Inflorescence raceme, 1 branch of shoot fork, several—25+–flowered, ca 40 mm diameter, spreading and horizontal near ground level or drooping, flowers alternate but cluster 1–sided with flowers reoriented on upper side and relatively flat, bracteate; peduncle to 20 mm long; rachis at flowering < 150 mm long, somewhat ridged with ridge descending from each bractlet, glabrous, glaucous; bractlet subtending pedicel conspicuously leaflike, sessile and firmly attached, acute–ovate, to 25 × 10 mm, photosynthetic, several–veined at base, ciliate on margins; pedicel cylindric, at anthesis to 15 mm long increasing 2× in fruit, with a tuft of soft hairs in the axil at the base.
Flower bisexual, bilateral, pealike (papilionaceous), ca. 20 mm across, flowers suberect from horizontal raceme, lacking fragrance; nectary on flat receptacle surrounding stalk of pistil, nectar–producing and collecting to the inside of stamens; calyx 4–lobed, 9—10 mm long, green with purplish patches at receptacle; tube bell–shaped slightly compressed side–to–side, 3.5—4.5 × 6.5 × 5.5 mm, 10–veined at base; upper lobe 2–toothed at tip (= 2 fused lobes), lower 3 lobes acute–triangular, < upper lobe, lobes soft short–hairy on both surfaces; petals 5, free, all projecting upward, clawed; banner ca. 22 mm long, projecting upward (not strongly bent or reoriented), claw flaring and channeled, 4.5—5 mm long, whitish, limb roundish, ca. 17.5 × 22 mm, pale light yellow sometimes with small purple spots in center, having fine radiating veins but inconspicuous, notched 2 mm at top; wings 2, 26—28.5 mm long, claw 6—6.5 × 2 mm, whitish, limb ± oblong, 20—22 × 11.5 mm, pale light yellow, with 2 backward–pointing basal lobes, upper lobe somewhat spongy with expanded surface tissue and whitish, lower basal lobe 1 mm shorter positioned at sinus of calyx lobes, rounded at tip; keel of 2 petals free, 3.5—4 mm < wings, claw 6—6.5 × 2 mm, white, flat, somewhat hatch–shaped with backward–pointing basal lobe on upper side, ca. 18 × 11 mm, pale light yellow; stamens 10 in 1 whorl, free; filaments butted tightly unequal, flat on outer side, 17—21 mm long within each flower, the 2 shortest the last to discharge pollen, pale green; anthers dorsifixed, dithecal, subequal, 1.6—2 mm long, light yellow–orange, longitudinally dehiscent; pollen yellow–orange; pistil 1, stalked (stipe), stalk ca. 2.5 mm long, white short–hairy approaching ovary; ovary superior, narrowly ovoid, ca. 4 × 1.3 mm, green but densely sericeous with upward–pointing hairs, 1–chambered with 12+ ovules attached to upper side but not in a single row; style gradually tapered and curved upward, greenish to green, sericeous to midpoint and glabrous above midpoint; stigma terminal, at level of the longest stamen, short–papillate.
Fruit pod (legume), dehiscent, 2–valved, several(—many)–seeded, ovoid, 17—30 × 8—16 mm long + long, persiste nt, flexible beak (style), dark brown, rough with irregular network of short, low ridges, ± strigose with upward–pointing hairs, valves dehiscing by also splitting beak, wall hard, chamber pubescent.
Seed ± kidney–shaped, 5—5.5 × 2.8—3.1 mm, resinous glossy brown to mustard with brown, surface with warty bumps beneath resin; hilum in center, 1 mm long.
A. C. Gibson