Lead plant is one of the few native shrubs on the prairies of Illinois. The common name may refer to the grayish color of the leaves or perhaps to an old belief that the plant was an indicator of lead ore deposits. Amorpha comes from the Greek amorphos meaning 'without shape or deformed" in reference to the small (-1/4 inch) flower which is reduced to a single petal; and canescens is Latin meaning 'gray-hairy". Lead plant is widely distributed throughout the prairies of Minnesota especially in mesic or dry areas. Individuals grow 1 to 2 feet tall. They are shrubby, meaning they have woody stems and their buds are above the ground, but they can bud from ground level if plants are burned or grazed. A member of the bean family, the leaves are compound, like most legumes, are 2 to 4 inches long, and are composed of - 25 pairs of grayish leaflets along a single axis (rachis).

Flowers are born on several terminal spikes. An individual spike may contain 50 to 100 flowers. The massing of so many small flowers and the contrast of the single purple petal and yellow stamens of each flower can only be appreciated at close range but it is one of the great joys of viewing this plant. When pollinated each flower produces a single seed, borne in a small, gray hairy pod. Seeds require both a cold period and heat to germinate. Heat can be provided by pouring boiling water over the seeds and then allowing the water to cool.

As a legume, lead plant is a host to nitrogen-fixing bacteria in its roots. The bacteria provide the plant with nitrogen in exchange for sugars that the plant produces through photosynthesis. These bacteria are available as inoculum from most native-seed suppliers. Intensive grazing will reduce the abundance of lead plant, and it does not tolerate cultivation. Periodic burning reduces plant size but increases plant number-a pattern found for many prairie legumes. I often use the presence of large lead plants or old, dead stems as a sign that an area has not been burned in the last several years.

Lead plant is one of 15 species of Amorpha present in the United States, and one of 3 species in Illinois. False indigo (Amorpha fruticosa) grows 5 to 6 feet tall, and the leaflets are larger and seem to be less hairy than those of lead plant. Dwarf wild indigo (Amorpha nana) is found in the western, dry prairies of Illinois. It is more diminutive in stature (-l foot tall), and the leaflets are greener and more rounded.