Shrubs, 0.4–1(–3) m; arising from thick, horizontal root­stock. Stems finely longitudi­nally grooved and ridged, often obscurely gland-dotted, sparsely puberulent or glabrous. Leaves (8–)15–25(–30) cm; stipules mostly acicular, 1.2–2.2 mm; petiole (3–)8–15(–18) mm, gland-dotted, sparsely puberulent or glabrous; rachis sparsely gland-dotted, often glabrous; leaflets (19–)23–33(–41), stipels acicular, 0.4–1.5 mm, petiolule (1–)1.5–2(–3) mm, gland-dotted, usually glabrous, blade elliptic to oblong or ovate to suborbiculate, (7–)12–25(–42) × (2.5–)5–9(–11) mm, base obtuse to round or truncate to subcordate, margins usually conspicuously revolute, crenulate, apex obtuse to round or emarginate, surfaces gland-dotted abaxially, glabrous or glabrate; midvein terminated by a swollen mucro, 0.2–0.5 mm. Racemes (1–)4–10-branched, (5–)10–25(–30) cm; rachis sparsely gland-dotted, sparsely puberulent; bracteoles linear to narrowly spatulate, 1.2–2.5 mm, gland-dotted, sparsely hairy. Pedicels (0.5–)1–1.8(–2.2) mm, gland-dotted, sparsely puberulent. Flowers: calyx tube turbinate to narrowly campanulate, (2–)2.2–3.2(–3.5) mm, distal 1/2 often gland-dotted, glabrous or glabrate; lobes: abaxial lobe narrowly triangular, slightly longer, adaxial lobes triangular or obtuse, 0.8–1.8(–2) mm; banner violet or white, broadly obcordate, (4.5–)5–6(–7) × 3–4.5 mm, distinctly clawed, margins entire or finely erose; filaments 6–9 mm, distinct; anthers yellowish; ovary glabrous. Legumes sessile, 4–6.5 × 1.8–2.5 mm, margins strongly curved outward abaxially, straight to slightly arched adaxially, distal 2/3 gland-dotted, glabrous. Seeds not seen.

Phenology: Flowering Feb–Aug(–Nov).
Habitat: Rocky margins of pine woodlands and coastal prairies of the Miami Rock Ridge.
Elevation: 0–10 m.

Distribution

• Generated Map
• Legacy Map

Fla.

Discussion

Amorpha crenulata is restricted to the Miami Rock Ridge of southeastern Florida, where about 350 indi­viduals remain in four populations confined to Miami-Dade County. Conservation measures for this species, including an ex situ collection, restored populations, and seed bank, are overseen by Fairchild Tropical Garden in Coral Gables (for example, J. Roncal et al. 2006; K. S. Wendelberger et al. 2007).

Amorpha crenulata is in the Center for Plant Conservation’s National Collection of Endangered Plants; as A. herbacea var. crenulata, it is listed in NatureServe as a plant of concern.

Selected References

None.

Lower Taxa

None.