Astragalus michauxii

Plants slender, 35–90(–95) cm, strigulose-pilosulous. Stems erect or ascending, with 5–10 well-developed internodes, glabrous or glabrate. Leaves (4.5–)7–17 cm; stipules 0.5–2.5 mm, papery-membranous at proximal nodes, herbaceous and membranous-margined at distal nodes; leaflet blades narrowly oblong, lanceolate-elliptic, narrowly oval, or sublinear, (3–)6–26 mm, apex retuse to obtuse, surfaces sparsely strigulose-pilosulous or, sometimes, glabrous adaxially or ciliate. Peduncles erect or incurved-ascending, 6–15 cm, together with racemes shorter than stems. Racemes (12–)15–40-flowered; axis 5–15(–18) cm in fruit; bracts 1–3 mm; bracteoles 0. Pedicels 0.6–3 mm. Flowers (13.5–)14.4–18.8 mm; calyx (5.7–)6–8.3 mm, strigulose, tube (4.7–)5–6.3 mm, lobes triangular to subulate, 1–2.3 mm; corolla banner recurved through 40°; keel 12.5–15 mm. Legumes brownish stramineous, strongly incurved, 23–31 × 4.5–6 mm, fleshy becoming stiffly leathery or subligneous, glabrous; septum 0.8–1 mm wide.

Phenology: Flowering Mar–Jun.
Habitat: Dry, sandy scrub-oak and pine woods.
Elevation: ca. 200 m.

Ga., N.C., S.C.

Discussion

Astragalus michauxii is known from the Atlantic Coastal Plain and Piedmont of southeastern Georgia to southeastern North Carolina. A report from central Florida should be disregarded since it is based on a Schallert specimen that probably came from North Carolina (D. Isely 1998). This is the only tall Astragalus from the southeastern United States, except for A. canadensis from the North Carolina mountains, that has connate stipules and much smaller fruits.

Selected References

None.

Lower Taxa