Pediomelum latestipulatum (Shinn.) Mahler var. appressum (Ockendon) L. E. Brown, broad–stipule scurfpea. Perennial herb, tuberous–rooted, not rosetted, 1–stemmed at base, initially unbranched later with 1—2 lateral branches, ascending to erect, to 35 cm tall; shoots with cauline leaves, at flowering foliage only above midplant, strigose with upward–pointing hairs, foliage gland–dotted and somewhat odorous when crushed.
Stems cylindric, to 3 mm diameter, tough, aboveground green or tinged reddish approaching canopy leaves and strigose, belowground glabrous with several sheathing prophylls, the prophylls < 10 mm long, each resembling a pair of fused stipules.
Leaves helically alternate, palmately compound with 5(7) leaflets, long–petiolate with pulvinus, with stipules; stipules 2, attached to stem node and base of petiole fused at base, 10—11 mm long, lobes acute–ovate, 2—3 mm long, short–ciliate on margins, gland–dotted above lobe midblade, parallel–veined; petiole ascending, 35—50+ mm long, tough, pulvinus small at base, inconspicuously striped, strigose; petiolule pulvinuslike, 1—1.5 mm long; blades of leaflets oblanceolate, 20—35 × 8—12 mm, < petiole, the central leaflet the longest, long–tapered at base, entire, rounded to obtuse at tip, pinnately veined, upper surface ± glabrous, lower surface strigose with upward–pointing hairs, finely gland–dotted.
Inflorescence raceme, axillary and terminal, ca. 20–flowered, flowers mostly 2—3 per node, clusters helically alternate, bracteate, strigose; peduncle < 20 mm long, green and purple–red striped beneath upward–pointing hairs; rachis somewhat zigzagged, with purple–red stripes and having ridges descending from bractlets; bractlet acuminate–ovate, at base 8.5—9 × 4—4.3 mm decreasing upward, purplish at base and on margins below midpoint, ciliate on margins, strigose along midvein on lower surface, gland–dotted, ± persistent; pedicel 2—3 mm long, strigose.
Flower bisexual, bilateral, pealike (papilionaceous). 6—8 mm across, 17—20 mm long; calyx 5–lobed, tube expanded and saclike on upper side, conspicuously gland–dotted; tube compressed side–to–side, 5.5—6 × ±6 mm but eccentric with longer upper side, purple with some green, with raised vein to each lobe, ± strigose, inner surface glabrous; lobes of 2 upper, 2 lateral, and 1 lower, upper lobes subequal, 7.5—8 × 2 mm, lower lobe 9.5—10 × ± 2.8 mm, lobes green, stiff–ciliate, lower lobe strigose along midvein, inner surfaces short–strigose; petals 5, clawed, glabrous; banner curved upward into saclike calyx tube, 20—21 mm long, claw inrolled and white expanding to base of 2 white, backward–pointing lateral lobes 9 mm from base, lateral lobes 2—2.5 mm long and dimpled, limb folded along midline, folded side ca. 4.5 mm wide, light purple to purple; wings 2, claw straight and linear, ca. 8.5 × 0.6—0.7 mm, white, base of limb with lobe 2—2.5 mm long, lobe and adjacent limb tissue white, limb oblong and rounded at tip, 8.5 × 3 mm, intense purple, with wrinkles; keel of 2 limbs fused above claws, 15 mm long, < wings and not fused with wings, claw ca. 8.5 × 0.6 mm, canoe–shaped limbs ca. 7 mm long, fused on lower edge from midpoint to tip, 3.5 mm wide, with a pair of small, backward–pointing, pale purple lobes at base, white tissue at base to intense purple and purple with lighter margins; stamens 10, diadelphous (9 fused + 1 free); filament of free stamen 13—13.5 mm long, white, filament sheet arched above base but straight above, fused nearly to expanded tip within keel, free portions triangular alternately long (1 mm) and short (0.5 mm), cream–colored; anthers dorsifixed, dithecal, ± 0.5 mm long,, dull yellow–orange, longitudinally dehiscent; pollen white; nectary disc oblique surrounding stalk of pistil (within stamens), longer on lower side (0.6 mm to 0.3 mm on upper side, producing thin nectar; pistil 1, ca. 15 mm long, with stalk (stipe) ca.1 mm long; ovary superior, ovoid compressed side–to–side, ca. 2 × 0.9 mm, green, at anthesis not appearing gland–dotted, 1–chambered with 1 ovule; style tapered from ovary and broadly hooked approaching tip, green with glands forming near base to white above without glands, occasionally with several strigose hairs on green lower side; stigma terminat, minute.
Fruit pod (legume), erect within calyx, 1–seeded, with thin, papery wall breaking irregularly at midpoint of seed, lower portion broadly elliptic compressed side–to–side and upper portion inversely narrowly funnel–shaped curved at tip and strongly compressed side–to–side, ca. 9 mm long, straw–colored conspicuously dotted with red glands, seed chamber 4 mm wide and elliptic in ×–section, breaking horizontally 2 mm from base, base remaining on short stalk; persistent calyx leathery, 12—13 mm long, light brown dotted with red glands, lobes stiff–ciliate.
Seed ± oval in outline, ca. 4 × 3 × 2.5 mm, dark green with light brown bump and patch near hilum, seed coat hard; hilum close to end of seed.
A. C. Gibson