The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Appalachian indigo-bush, mountain false indigo

dwarf false indigo, dwarf indigo, dwarf indigobush

Habit Shrubs, 1–2 m; arising from compact, woody root. Shrubs, (0.1–)0.3–0.6(–1) m; usually rhizomatous.
Stems

smooth, sparsely gland-dotted or eglandular, usually glabrous, sometimes glabrate.

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

Leaves

(10–)14–22(–30) cm;

stipules linear to linear-lanceolate, 2.5–4.5 mm, eglandular, slightly hairy or margins ciliate;

petiole (16–)20–40(–60) mm, sparsely gland-dotted or eglandular, glabrous or sparsely puberulent;

rachis sparsely gland-dotted, glabrous or, rarely, sparsely puberulent;

leaflets (9–)11–15(–19), stipels acicular to setaceous, 1.2–2 mm, petiolule 2–4(–5.5) mm, sparsely gland-dotted, usually glabrous, blade often elliptic to oblong, sometimes ovate to, rarely, orbiculate, (14–)20–45(–75) × (10–)14–28(–36) mm, base round to truncate or subcordate, margins slightly revolute, entire or slightly crenulate, apex obtuse to broadly round or emarginate, surfaces gland-dotted, mostly glabrous;

midvein terminated by a slightly swollen mucro, 0.2–0.4 mm.

(1.5–)3–7(–10) cm;

stipules linear or setaceous, (2–)3–5(–6.5) mm;

petiole (2–)4–8(–10) mm, usually gland-dotted, mostly strigulose, sometimes glabrous;

rachis gland-dotted, puberulent or glabrous;

leaflets (7–)13–27(–41), stipels acicular, (1–)1.5–2.5(–3) mm, petiolule 0.7–1 mm, gland-dotted, especially abaxially, mostly pubescent to glabrate, blade usually elliptic to oblong or ovate, rarely obovate to suborbiculate, (2–)6–13(–18) × (2–)3–6(–8) mm, base mostly round, margins usually somewhat revolute, entire or inconspicuously crenulate, apex round to truncate or emarginate, surfaces glabrous, margins puberulent;

midvein usually terminated by a slender mucro, (0.6–)0.8–1.2(–1.5) mm.

Racemes

1–3(or 4)-branched, (5–)10–18(–28) cm;

rachis gland-dotted, usually glabrous;

bracteoles usually narrowly lanceolate, (0.5–)0.8–1.5(–2) mm, eglandular, puberulent, often ciliate.

unbranched, (2–)3–7(–9) cm;

rachis eglandular, usually puberulent;

bracteoles linear to narrowly spatulate, (2.5–)3–4(–5) mm, eglandular, puberulent.

Pedicels

(0.8–)1–2.5(–3) mm, eglandular, usually glabrous.

1–2(–2.5) mm, eglandular, usually puberulent.

Flowers

calyx tube broadly turbinate to campanulate, 2–3(–3.2) mm, eglandular, glabrous except rim ciliate;

lobes obscure or developed, then rounded to broadly triangular-dentate, 0–0.6(–0.8) mm;

banner purplish, broadly obcordate, (4.5–)6–8(–8.5) × 4–6 mm, clawed, margins entire or erose;

filaments 8–11 mm, connate basally 3–4.5 mm;

anthers golden yellow to orange;

ovary glabrous.

calyx tube turbinate, (1.5–)1.8–2(–2.2) mm, at least distal 1/2 gland-dotted, glabrous;

lobes triangular to narrowly lanceolate, (0.8–)1–2(–2.2) mm;

banner dark reddish purple, broadly obcordate, 4.5–6 × 3.5–4.5 mm, distinctly clawed, margins finely erose, apex emarginate;

filaments 6–8 mm, connate basally 0.5–1 mm;

anthers purplish;

ovary glabrous.

Legumes

sessile, (6.5–)7.5–9(–10) × (2.5–)3–4(–4.5) mm, margins distinctly curved outward abaxially, straight or nearly so adaxially, at least distal 2/3 gland-dotted, glabrous.

sessile, 4.5–5.5 × 2–2.8 mm, margins curved outward abaxially, straight adaxially, at least distal 2/3 gland-dotted, glabrous.

Seeds

not seen.

olive brown, 2.5–3 × 1–1.5 mm, reticulate.

2n

= 20.

Amorpha glabra

Amorpha nana

Phenology Flowering May–Jul. Flowering May–Jul.
Habitat Dry to moist thickets and woods, pine-oak heath ridges. Prairies, hillsides, buttes, sandy soils, clay soils if well-drained, in prairies, prairies on shale slopes, usually calcareous soils.
Elevation (30–)400–1200 m. ((100–)1300–3900 ft.) 200–2200 m. (700–7200 ft.)
Distribution
from FNA
AL; GA; NC; SC; TN
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; IA; KS; MN; ND; NE; NM; OK; SD; MB
[WildflowerSearch map]
[BONAP county map]
Discussion

Amorpha glabra is listed as a species of concern in South Carolina.

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

Amorpha nana is listed as threatened by the state of Iowa; it is encountered more commonly in the northern and western parts of its range.

(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. confusa, A. crenulata, A. fruticosa, A. georgiana, 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. nitens, A. ouachitensis, A. paniculata, A. roemeriana, A. schwerinii
Synonyms A. microphylla
Name authority Desfontaines ex Persoon: Syn. Pl. 2: 295. (1807) Nuttall: Cat. Pl. Upper Louisiana, no. 5. (1813)
Web links