Herbs or subshrubs, prostrate, 0.5–1.5 m, armed or unarmed. Stems ribbed, glabrous; prickles sparse along ribs, recurved. Leaves: stipules linear or filiform, 2–3.5 mm, glabrous; petiole (2–)2.5–3(–4) cm; primary rachis 2.5–3.5 cm; pinnae 1–3 pairs; leaflets 9–14 pairs, blades obliquely linear, 3.5–6 × 0.7–1(–1.4) mm, margins ciliate, 1 eccentric vein evident abaxially, apex acute, mucronulate, surfaces glabrous. Peduncles 1–5 cm. Inflorescences 35–40-flowered, axillary, globose capit­ula, solitary, 10–12 mm diam.; bracts spatulate, 1/4–1/3 corolla length. Pedicels 0.2 mm. Flowers bisexual and staminate; calyx campanulate, lobes 5, 1/5–1/4 corolla length; corolla pink, glabrous, lobes 5, 1/4–1/3 corolla length; stamens 10, filaments connate at bases, pink; ovary stipitate, glabrous; style attenuate at apex; stigma tubular. Legumes sessile, straight, linear-oblong, tetragonal, (45–)70–90(–100) × 4–4.5(–5) mm, not con­stricted between seeds, valves entire, 1–2.5 mm wide, margin 2.5–3.5 mm wide, prickly or unarmed, apex rostrate, rostrum 5–10 mm, faces glabrous. Seeds (6–)10–16, dark brown, oblong or subrhomboid, 5–6 × 2.5–3 × 1.5 mm, testa porous, fissural line 90%.

Phenology: Flowering Apr–Jun; fruiting May–Aug.
Habitat: Dry sandy or gravelly places.
Elevation: 100–200 m.

Distribution

• Generated Map
• Legacy Map

Tex., Mexico (Coahuila).

Discussion

Mimosa monclovensis occurs in southern Texas, southward from San Antonio, according to R. C. Barneby (1991, treated as M. quadrivalvis var. nelsonii).

Mimosa subinermis (S. Watson) B. L. Turner, not M. subinermis Bentham (1841), is an illegitimate name that pertains to M. monclovensis.

Selected References

None.

Lower Taxa

None.