Vicia ludoviciana Torrey & A. Gray subsp. leavenworthii (Torrey & A. Gray) Lassett. & C. R. Gunn, leavenworth vetch, deerpea vetch. Annual vine, taprooted, with tendrils, several–stemmed at base, branched, sprawling and climbing over other plants; shoots somewhat 2–dimensional (plagiotrophic) or not, short–villous (villous); tendril = terminal portion of blade, unbranched to unequally 3–branched, the branches modified leaflets; roots nodulated.
Stems 3—5–angled, in range < 2 mm diameter, with 3 ridges descending from petiole midvein and stipules, flexible, internodes < 30 mm long, green or ridges purplish.
Leaves helically alternate, 1–pinnately compound with (4—)8—16 alternate and subopposite leaflets, short–petiolate, with stipules; stipules 2, ± equal in a pair, spreading, 2–lobed, asymmetric, linear–lanceolate to linear (lanceolate) commonly with an outpointing, ⊥ basal lobe, 1.4—3.5 × 0.5—0.7 mm and basal lobe < 1 mm long, green with red–purple, soft–hairy to glabrescent; petiole slightly channeled, 1.5—3.5(—5) mm long, often red–purple, soft–hairy; rachis shallowly channeled with leaflets attached to the edges of channel, to 40 mm long below tendril, green but red–purple where leaflets attached, short–villous; petiolules to 0.6 mm long, pale green (whitish), sparsely hairy; blades of leaflets elliptic or oblong to ovate (obovate), 7—11 × 2.5—5.5 mm, tapered at base, entire, rounded (obtuse) with short point at tip, pinnately veined with midrib slightly raised on lower surface, dull green, in range surface soft–hairy; tendril shallowly channeled at base to nearly cylindric approaching tip, principal axis to 30 mm long, sometimes pinkish.
Inflorescence 2—5–flowered raceme, axillary, in range no more than midpoint on the adjacent leaf, lacking bracts, soft–hairy and green tissue with minute glandular hairs; peduncle ca. 4–ridged, at anthesis 6—25 mm long increasing some in fruit, green with purplish ridges, flexible, short–strigose; rachis short extending beyond last flower by 1.5—2 mm; pedicel 0.5—1 mm long, with decurrent base along rachis.
Flower bisexual, bilateral, pealike (papilionaceous), 1—1.5 mm across, 5 mm long; calyx 5–lobed, 3.5—4 mm long, short–villous with minute glandular hairs; tube bell–shaped compressed side–to–side, ± 1.5 mm long, green and reddish, not inflated or pouched; lobes unequal, linear to narrowly triangular flared at base, 1.1—2.3 mm long, the lower lobe longer; petals 5, banner strongly folded over flower, not clawed, obovate and shallowly 2–lobed, ca. 5 × 4 mm, light violet at base and above midpoint with white between with ascending darker veins; wings 2, adherent to keel, clawed, claws linear, 1 mm long, white, lobe oblong–obovate, ca. 4 × 1.3 mm, toothed at base, the tooth basally pointed on upper edge of wings ca. 0.6 mm long, white; keel of 2 petals fused base nearly to tip, curved upward, white with dark purple blotches on exposed portion, notched at tip; stamens 10, diadelphous (9 filaments fused and 1 free); filament sheet 2.8—3.1 mm long, whitish, free portions ca. 1 mm long, white, arching upward 90°, the free filament flat and flared tapered from broad base; anthers dorsifixed, dithecal, of 2 sizes, 0.25—0.3 mm long and 0.4 mm long, orange–yellow, longitudinally dehiscent; pollen pale orange–yellow; pistil 1, with short stalk (stipe); ovary superior, elliptic compressed side–to–side, ca. 2.5 × 0.7 mm, green, glabrous, 1–chambered with to 7 ovules attached to upper side; style to 1.5 mm long, bent sharply (90°) at base, white above bend, short–hairy on 0.5 mm of style and tip; stigma minute–capitate.
Fruit pod (legume), dehiscent, 2–valved, 6—7–seeded, ± oblong slightly compressed side–to–side, 18—22 × 4 mm, tapered at base, prowlike and short–beaked at tip, not veiny, not bulging at seeds, glaucous brown with purple blotches.
Seed subspheroid, 2—2.4 × 1.8—2 mm, dull olive to dark olive–brown with black spots and blotches, having hard seed coat; hilum 1—1.5 × 0.25 mm, brown.
A. C. Gibson