Amorpha fruticosa L. - False Indigo

Amorpha fruticosa plant

Family - Fabaceae

Stems - Woody, multiple. A shrub to +3m tall. Young branches pubescent.

Leaves - Alternate, odd-pinnate. Leaflets typically oblong, entire, mucronate, opposite, pubescent to glabrous above and below.

Amorpha fruticosa leaf

Inflorescence - Terminal and axillary racemes to +15cm long, +/-1.3cm in diameter. Pedicels to 3mm long.

Flowers - Corolla of single petal, deep violet-purple, to 5mm long. Petal falsely tubular and surrounding other floral organs. Stamens 10, monodelphous, slightly exserted. Filaments glabrous, white, 4-5mm long. Anthers orange, .6mm long. Style purplish, pubescent, 5mm long, exserted. Fruits to 7mm long, glabrous or sparsely pubescent. Calyx pubescent, tubular, campanulate, 2.5mm long, 5-lobed. Lobes unequal, shallow. Lowest lobe acute.

Amorpha fruticosa flowersFlowers close-up.

Flowering - May - June.

Habitat - Moist ground, gravel bars. Also cultivated.

Origin - Native to U.S.

Other info. - This striking shrub can be found throughout Missouri.
I believe Steyermark lists 5 varieties for this plant mostly based on leaf and stem pubescence. I won't go into those here. There is also a hybrid plant between A. fruticosa and A. canescens. This plant is called Amorpha X notha Palmer.
The genus name means "without shape", referring to the single-petaled corolla.

Photographs taken in the Ozark National Scenic Riverways, Shannon County, MO., 5-19-03.


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