Are both Promenaea and Machaeranthera from North America?
Promenaea Promenaea is a genus of flowering plants from the orchid family, Orchidaceae. It contains 18 currently accepted species (including one that is apparently extinct), all endemic to Brazil.
Leucaena Leucaena is a genus of flowering plants in the mimosoid clade of the subfamily Caesalpinioideae of the legume family Fabaceae. It contains about 24 species of trees and shrubs, which are commonly known as leadtrees. They are native to the Americas, ranging from Texas in the United States south to Peru. The generic name is derived from the Greek word λευκός ("leukos"), meaning "white," referring to the flowers.