Common Name: Lead Plant

General Information

Amorpha canescens is a perennial plant with stems that become more or less woody and usually persist. It produces a clump of branched stems up to 1 metre tall from a rhizomatous rootstock[].
The plant is harvested from the wild for local use as a medicine and a tea, and can also be used as an insecticide. It is used in shelterbelts and to stabilize soils, and is often grown as an ornamental, valued especially for its flowering display.
Plants can become invasive in the garden when grown in rich soils[].

Known Hazards

None known

Botanical References

, ,

Range

Central N. America - Alberta to Saskatchewan and Michigan, south to New Mexico and Texas

Habitat

Dry sandy prairies, glades, hills and open woodland[, , ].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	0.75 m
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Amorpha canescens is a very hardy plant, tolerating temperatures down to about -25°c[, ] but it frequently dies down to ground level in the winter, resprouting from the base in the following spring[]. It grows in areas where the mean annual precipitation is in the range 380 - 1,140mm[].
Prefers a light well-drained sandy soil in full sun or light shade[, , ]. Tolerant of poor dry soils, plants can be invasive in rich soils[]. Thrives in sandy to silt-textured soils, and is also tolerant of weakly acid to moderately alkaline and weakly saline soils[]. Wind resistant[]. Established plants are drought tolerant[].
A deep rooted plant, it thrives best in hot, droughty seasons[]. It only ripens its seed in fine autumns[].
Immune to insect pests, the plant contains its own insecticide[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

An infusion of the dried leaves makes a pleasant tasting yellow-coloured tea[, , , ].

Medicinal

An infusion of the leaves has been used to kill pinworms or any intestinal worms[]. The infusion is also used to treat eczema, the report does not say it if is used internally or externally[]. The dried and powdered leaves are applied as a salve to cuts and open wounds[].

A decoction of the root is used to treat stomach pains[].

A moxa of the twigs has been used in the treatment of neuralgia and rheumatism[].

Agroforestry Uses:

At one time this plant was supposed to indicate the presence of lead in the soil[].
Plants have an extensive, deep, branching woody root system that can extend to a depth of 5.3 metres and also fixes atmospheric nitrogen. They tolerate poor dry soils and are also wind resistant, they are used as a windbreak and also to prevent soil erosion[, ].

Other Uses

Resinous pustules on the plant contain 'amorpha', a contact and stomachic insecticide that also acts as an insect repellent[, ].

Propagation

Seed - best sown as soon as it is ripe when it requires no pre-treatment. Stored seed develops a hard seedcoat and benefits from scarification before sowing in order to speed up and improve germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing[, ]. Sow early spring in a greenhouse[, ]. The seed usually germinates in 1 - 2 months at 20°c[]. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, early summer/July in a frame. High percentage[].
Cuttings of mature wood of the current seasons growth, autumn, in a sheltered position outdoors. Takes 12 months[].
Suckers in spring just before new growth begins[].
Layering in spring .