Description
Senna multiglandulosa (previously Cassia multiglandulosa)
Commonly known as glandular senna, downy senna, or buttercup bush, this pea family nitrogen fixer is native to the humid highlands of Mexico, Guatemala, and western parts of South America. Typically growing to height of up to 4 m, this shrub has pinnate leaves, and masses of attractive bright yellow flowers in late winter, which are glossy like buttercups. These are followed by dramatic long brown seedpods in autumn.
Surprisingly, given its origins, Buttercup Bush does well in a variety of environments – it tolerates a wide variety of soils including sand and clay, also both humid and semi-arid environments, and mature plants can survive frosts and light freezes. Even small plants tolerate light frosts here in Hawke’s Bay. Like many nitrogen fixers, this shrub does require full sun.
Senna species are widely used in Africa, Asia, Europe and Latin America for their medicinal benefits. Some Senna species are well-known for their antimicrobial and anti-inflammatory activities with basis in traditional medicine to treat diabetes, microbial infections, malaria fever and other ailments. This species has been used to protect against fever, typhoid, and dysentery. The flowers are edible and are used in stews. The roots, stems and leaves are used for dyes, and the branches are often used for basket making.
We are making good use of this plant, primarily as a nitrogen fixer, in our food forest here in Hawke’s Bay. I do find it has a tendency to become top heavy and benefits from staking when young, but even plants which have fallen sideways or broken never seem the worse for wear, they just carry on growing away merrily! Upright plants do not cast heavy shade and can be easily grown above groundcovers and shrubs. Leaves can be ‘chopped and dropped’ periodically for a nitrogen-rich mulch.
Certified organic plant in deep root 11cm pot. Plants are 30-40cm high
Flower Photo Credit: Stan Shebs
Other photos: Kahikatea Farm
