Dalea formosa

Shrubs, relatively erect, often gnarled, glabrous or glabrate proximal to inflorescences. Stems 1.5–9 dm, eglandular or sparsely glandular-tuberculate distally. Principal leaves 0.3–1.1 cm; leaflets (5 or)7–13(or 15), blades obovate-cuneate to oblanceolate, 1–6(–7) mm. Peduncles 0–1(–1.8) cm. Inflorescences spikes, loosely flowered, 2–9-flowered, not involucrate, 8 mm diam.; axis usually visible, 0.2–0.8(–3.5) cm; bracts early deciduous or ± persistent, brown, 2–6 mm, glandular. Calyces asymmetric, not recessed opposite banner, opening oblique, (7.5–)8.5–13.5(–16.2) mm, long-pilose; tube (3–)3.5–5(–5.2) mm, with 3 or 4(or 5) prominent blister glands between ribs, lobes lanceolate-acuminate, becoming aristate, plumose, with pointed projecting glands laterally. Corollas bicolored, banner cream to pale yellow, reddish in age, epistemonous petals rose- or magenta-purple; papilionaceous; banner (6.6–)7–8.8 mm, blade deltate-obcordate, (4–)4.3–5.5 × (3.4–)4–6.4 mm; epistemonous petals attached proximal to middle of stamen tube; wings 5.2–7.4 × 2.4–3.7 mm; keel connate valvately, blades (6–)6.3–7.6 × 3.2–4.5 mm. Stamens 10, 9–12.5 mm, filaments distinct to 2.4–4.5 mm, anthers 0.8–1.2 mm. Legumes 3–3.5 mm, pilosulous and gland-dotted distally. Seeds 2.8–3 mm. 2n = 14, 21, 42.

Phenology: Flowering spring (fall).
Habitat: Rocky desert, grasslands, open woodlands.
Elevation: 500–2100 m.

Distribution

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Ariz., Colo., N.Mex., Okla., Tex., Mexico (Chihuahua, Coahuila, Sonora).

Discussion

As R. C. Barneby (1977c) pointed out, Dalea formosa is distinctive in appearance. It is complex cytologically, with diploid plants known from Arizona, New Mexico, Texas, and Mexico; tetraploid plants from Texas and Mexico; and hexaploid plants from New Mexico, Texas, and Mexico (R. Spellenberg 1981). In Texas, the species is known from widespread areas of the western half of the state.

Selected References

None.

Lower Taxa

None.