False indigo-bush is a 6-12 ft., loose, airy shrub which often forms dense thickets. Plants develop a leggy character with the majority of their pinnately compound, fine-textured foliage on the upper third of the plant. Leaflets velvety on the lower surface, margins frequently almost parallel, often abruptly rounded at both ends and with a notch at the tip. Flowers small, purple to dark blue with yellow stamens extending beyond the single petal,crowded in narrow, 3-6 in., spikelike clusters at or near the ends of the branchlets, appearing from April to June. Fruit small, up to 3/8 inch long and with blisterlike glands visible under a 10x hand lens. This is a deciduous plant.This shrub, which often forms thickets on riverbanks and islands, can be weedy or invasive in the northeast. Another False Indigo (A. herbacea) has whitish to blue-violet flowers in fan-like masses on top of the plant and gray-downy foliage with up to 40 leaflets. The genus name, from the Greek amorphos (formless or deformed), alludes to the fact that the flower, with only a single petal (the banner or standard), is unlike the typical pea flowers of the family.