Dalea drummondiana Shinn. var. drummondiana, drummond prairie–clover. Perennial herb, not rosetted at base, several–stemmed at base, principal branches spreading with many leaves of unexpanded axillary shoots, in range to 30 cm tall; shoots with only cauline leaves, loosely pubescent with fine, non–straight hairs, conspicuously gland–dotted having raised glands on stems and leaves, pleasantly aromatic when crushed.
Stems cylindric, to 4 mm diameter, sometimes red–tinged and older stems fainting striped.
Leaves helically alternate, odd–1–pinnately compound with (4—)6—9 pairs of subopposite to opposite lateral leaflets, petiolate with pulvinus, with stipules; stipules 2, attached to base of petiole, narrowly acuminate to linear, < 3 mm long, often tinged purple–red, pubescent, ± persistent; petiole to 5.5 mm long, curved outward, pulvinus < 1 mm long, white to pale green, above pulvinus narrowly channeled, glands to 0.3 mm across; rachis channeled, 9—15 mm long; petiolules ± 0.4 mm long, white, with several hairs; blades of leaflets elliptic to narrowly obovate, 3—4.5 × 1—1.8 mm, thickish, entire, acute at tip, 1–veined and somewhat folded upward from midrib, upper surface short–pilose, lower surface with conspicuous glands. Inflorescence: spike, terminal on principal branches, initially narrowly cone–shaped, 8—9 mm diameter, to 75 mm long and cylindric in fruit, many–flowered, flowers helically alternate in ca. 13 files and tightly arranged with short internodes, bracteate, finely puberulent and with conspicuously raised glands; peduncle ± ridged, < 75 mm long above the uppermost cauline leaf, tough; rachis densely soft–hairy; bractlet subtending flower with upper portion arching over flower bud, acuminate maturing triangular, ca. 3 × 1 mm, purple–red, keeled below midpoint, short–pilose and pilose on outer (lower) surface and glabrous on upper surface, with 2 opposite bracteoles at base of flower, bracteoles linear, ca. 0.5 mm long, white aging reddish, persistent.
Flower bisexual, ± bilateral, ca. 5 mm across; calyx 5–lobed, ± 3–sided and compressed by adjacent flowers and bractlets, ca. 2.5 mm long; tube cup–shaped, white, having 3 hairy ridges to sinuses of upper lobes, densely soft–hairy with downward–pointing short–hairs; upper lobes 2 deltate and lower 3 lobes triangular–ovate, ca. 1 mm long, broadly acute to rounded, with a deep sinus between deltate lobes, green aging dark red or with some green, having a conspicuous ring of raised glands in red portion, outer surface glabrous or glabrate, inner surface densely soft–hairy; petals 5, banner free, wings and keel petals fused to stamens alternating with free filaments, clawed, pure white; banner ca. 5.5 mm long, claw linear, 3—3.3 mm long, limb inversely heart–shaped to broadly arrow–shaped, and somewhat cupped upward (never flat), 2.1—2.5 × 2.2—2.5 mm, broadly acute to rounded at tip; wings 2 and keels 1, equal, claws slender, 1.2—1.4 mm long, limbs oblanceolate, 2.7—5 × 0.5—0.6 mm, obtuse to acute at tip; stamens 5, monadelphous (5 fused as a sheet), sheet at top having 5 exserted filaments alternating with 4 exserted petals (2 wings + 2 keel petals, sometimes interpreted as staminodes); filament sheet open with ovary bulging out on upper side, 1.6—1.8 mm long, white, free filaments spreading, 2—2.5 mm long, white; anthers dorsifixed, dithecal, 1—1.1 mm long, bright yellow to orange–yellow, longitudinally dehiscent; pollen yellow; nectary tissue at base of ovary, nectar–producing, nectar thin; pistil 1; ovary ovoid, 1 × 0.7 mm, ± green, densely short–villous, 1–chambered with 2 ovules; style straight to midpoint then curving upward, ca. 4.5 mm long, white, densely short–villous on lower style on upper side; stigma terminal, exserted above anthers, minute.
Fruit pod (legume), indehiscent, 1–seeded, abscised within pubescent calyx, hatchet–shaped compressed side–to–side, ca. 2.3 × 1.8 mm, colorless at base to tannish around short–villous above midpoint, lacking conspicuous glands.
Seed heart–shaped, ca. 1.4—1.6 mm, dull brown, hard.
A. C. Gibson