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savanna false indigo or indigo-bush

dark indigo-bush, shining false indigo

Habit Shrubs, 0.3–1.4 m; arising from compact, woody root. Shrubs, 1–2(–3) m; arising from compact, woody root.
Stems

finely longitudinally grooved and ridged, gland-dotted, strigulose to glabrate.

smooth, usually eglandular, mostly glabrous or puberulent.

Leaves

(8–)12–20(–26) cm;

stipules sometimes persistent, linear or setaceous, (1–)1.5–2(–2.5) mm;

petiole (6–)8–15(–20) mm, gland-dotted, puberulent or glabrous;

rachis sparsely gland-dotted, puberulent or glabrous;

leaflets (11–)15–31(–35), stipels acicular or setaceous, 0.8–1.8 mm, petiolule 0.7–1.5(–1.8) mm, gland-dotted, mostly puberulent or glabrous, blade elliptic to oblong or ovate to suborbiculate, (10–)15–25(–35) × (7–)9–15(–18) mm, base truncate or round to subcordate, margins usually revolute, entire or inconspicuously crenulate, apex round to obtuse or emarginate, surfaces sparsely to conspicuously gland-dotted, usually glabrous or glabrate, sometimes sparsely pubescent abaxially;

midvein terminated by a slender mucro, (0.2–)0.4–1 mm.

10–18(–22) cm;

stipules linear to narrowly setaceous, 3–5 mm, sometimes sparsely gland-dotted, short-pilose;

petiole (15–)20–35(–50) mm, eglandular, usually glabrous;

rachis eglandular, usually glabrous;

leaflets (7–)9–15(–19), stipels not seen, petiolule 2–5(–7) mm, eglandular, glabrous or pilosulous, blade drying blackish, usually elliptic to oblong, sometimes ovate, 20–40(–70) × (10–)15–35(–45) mm, base round, margins flat, entire, apex usually emarginate, sometimes round, surfaces distinctly shiny adaxially, usually glabrous and eglandular, rarely sparsely puberulent and sparsely gland-dotted abaxially;

midvein terminated by a slender mucro, 0.1–0.2 mm.

Racemes

(1–)3–5(–8)-branched, 10–20(–30) cm;

rachis sparsely gland-dotted, puberulent;

bracteoles linear to narrowly subulate, 1.5–2.5(–3) mm, usually eglandular, sparsely pubescent or sparsely ciliate.

1–3(–8)-branched, (5–)8–15(–25) cm;

rachis usually eglandular, usually glabrous, sometimes puberulent;

bracteoles drying blackish, linear to setaceous, 1.5–3(–4) mm, usually eglandular, glabrous or short-pilose.

Pedicels

0.4–1 mm, eglandular, sparsely pubescent.

drying blackish, 1–2.2 mm, eglandular, glabrous or short-pilose.

Flowers

calyx tube turbinate to narrowly campanulate or cylindric, 1.7–2.2 mm, distal 1/3–2/3 rarely gland-dotted, glabrous;

lobes: abaxial lobe acuminate, slightly longer, adaxial lobes triangular to acuminate, 0.4–1.2(–1.5) mm, margins densely ciliate;

banner bright blue, broadly obovate to obcordate, (4–)5–6 × 3–3.5(–4) mm, distinctly clawed, margins entire or finely erose;

filaments 5–8 mm, distinct;

anthers yellow;

ovary pubescent.

calyx drying blackish, tube usually funnelform to obconic, rarely campanulate, 2–2.5 mm, usually eglandular, glabrous or short-pilose;

lobes: abaxial lobe triangular, slightly longer, adaxial lobes round to triangular, 0.2–1.4 mm;

banner reddish purple, broadly obovate, 4.5–6 × 3–4.8 mm, obscurely clawed, margins entire or irregularly erose;

filaments 5–7 mm, connate basally 2–2.5 mm;

anthers yellow;

ovary glabrous.

Legumes

sessile or stipitate, 4–5.5 × 2–2.5 mm, margins curved outward abaxially, straight adaxially, at least distal 1/2–2/3 gland-dotted, glabrous.

short-stipitate, 6–8 × 2.5–3.5 mm, margins curved outward abaxially, straight or slightly curved inward adaxially, rarely at least distal 1/3 gland-dotted, glabrous.

Seeds

olive brown or brown, 2–2.3 × 1–1.5 mm, smooth, lustrous.

not seen.

Amorpha confusa

Amorpha nitens

Phenology Flowering (May–)Jun–Jul. Flowering Apr–Jun.
Habitat Pine woodlands, savannas, and road banks in outer Atlantic Coastal Plain. Moist thickets and woods.
Elevation 0–50 m. (0–200 ft.) 50–600 m. (200–2000 ft.)
Distribution
from FNA
NC; Pine woodlands; savannas; and road banks in outer Atlantic Coastal Plain
[BONAP county map]
from FNA
AL; AR; GA; IL; KY; LA; OK; SC; TN
[BONAP county map]
Discussion

Amorpha confusa is known presently only from Brunswick and Columbus counties; it is believed to be extirpated in adjacent South Carolina. The taxon is a Federal species of concern and is listed as threatened in North Carolina. It is usually encountered growing in loamy soils, most often of the Foreston soil series.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Amorpha nitens is listed as endangered by the state of Illinois and as a species of special concern in Georgia; it is considered to be a sensitive species in the Shawnee National Forest by the United States Forest Service. Amorpha nitens and A. fruticosa share most of their characters and differ most distinctively by the tendency to blacken upon drying ascribed to A. nitens, although some A. fruticosa individuals can blacken upon drying as well.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Amorpha Fabaceae > subfam. Faboideae > Amorpha
Sibling taxa
A. californica, A. canescens, A. crenulata, A. fruticosa, A. georgiana, A. glabra, A. herbacea, A. laevigata, A. nana, A. nitens, A. ouachitensis, A. paniculata, A. roemeriana, A. schwerinii
A. californica, A. canescens, A. confusa, A. crenulata, A. fruticosa, A. georgiana, A. glabra, A. herbacea, A. laevigata, A. nana, A. ouachitensis, A. paniculata, A. roemeriana, A. schwerinii
Synonyms A. georgiana var. confusa
Name authority (Wilbur) S. C. K. Straub: Sorrie & Weakley, J. Bot. Res. Inst. Texas 3: 154. (2009) F. E. Boynton: Biltmore Bot. Stud. 1: 139. (1902)
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