Macroptilium lathyroides

Herbs, biennial; root elongate. Stems erect or semierect, with hollow pith, glabrescent. Leaves: stipules retrorse, lanceolate, 42–60 × 8–15 mm; petiole 1.8–4.5 cm, glabrescent; rachis 5–11 mm; stipels linear, 1–1.8 mm; leaflets membranous, blades ovate, elliptic, or oblong, base attenuate, apex acute, surfaces strigulose abaxially, glabrescent adaxially; lateral blades 2–4.5 × 0.6–2 cm, terminal blades 2–5.5 × 0.6–4 cm. Inflorescences 19–46 cm, axes glabrous; tufts of bracts at base of peduncle persistent, 3.3–6.3(–7.5) mm, triangular, puberulent; extrafloral nectaries conspicuous at nodes; bracts and bracteoles subulate. Pedicels 0.8–1.9 mm. Flowers 2–2.6 cm; calyx tubular, 3–7 mm, strigose or glabrescent, calyx lobes shorter than tube; corolla red; banner oblong, 9.5–15 × 8–9 mm; wings oblong, 11.5–26 × 6.5(–12) mm; keel 9–16 mm; ovary nectary disc distally oblique; ovules 24. Legumes patent, linear, 9.5–10.5 × 0.2–0.3 cm. Seeds 15–20, oblong, 2.5–4.4 × 2.5 mm, valves twisting at dehiscence. 2n = 22.

Phenology: Flowering May–Nov.
Habitat: Disturbed sites, flat pinelands, oak forests, grassy sandy fields.
Elevation: 0–20 m.

Introduced; Fla., Ga., La., S.C., Mexico, West Indies, Central America, South America, introduced also in Asia, Africa, Australia.

Discussion

Macroptilium lathyroides is relatively common throughout central and southern peninsular Florida; other occurrences in the flora area are mainly in the Coastal Plain. A report of M. lathyroides as a nursery weed in Texas (J. Aplaca 2012) has not been confirmed.

Lotus maritimus Vellozo is an illegitimate name that pertains here.

Selected References

None.

Lower Taxa