Amorpha is a genus of plants in the pea family, Fabaceae. All the species are native to North America, from southern Canada, most of the United States (US), and northern Mexico. They are commonly known as
false indigo. The name
Amorpha means "deformed" or "without form" in Greek and was given because flowers of this genus only have one petal, unlike the usual "pea-shaped" flowers of the Faboideae subfamily.
Amorpha is missing the wing and keel...
(Wikipedia)