Senna corymbosa aka Argentine Senna

Senna corymbosa, also known as Argentine senna, Argentina senna, buttercup bush, flowering senna, Texas flowery senna or tree senna, is an ornamental plant in the genus Senna. It is a bushy evergreen shrub with pinnate leaves composed of lance-shaped leaflets. During late summer, it produces corymbs of bright yellow flowers measuring 2cm across, which are borne in the leaf axils. This tender, rounded shrub is native to Argentina, Brazil, and Uruguay and is well-adapted to tropical and dry climates. It is particularly renowned for its vigorous growth and heavy flowering, making it an excellent choice for warm climate gardens. While it typically blooms heavily throughout the year, its peak flowering period is from fall through winter into spring. In frost-free zones, it may drop its leaves and cease flowering during midwinter, resuming blooming in the summer. In colder regions, hard winter freezes cause it to die back to the roots, leading to new growth in spring and blooming in late summer. Senna corymbosa can be grown as a shrub, pruned into a flowering tree, or espaliered onto sunny, warm walls. However, it is important to note that this plant is considered a weed by international botanical authorities and may become invasive in certain regions.