About Senna siamea (Lam.) H.S.Irwin & Barneby
Growth Form and Flowers
Senna siamea is a medium-sized evergreen tree that grows up to 18 meters (60 feet) and produces yellow flowers.
Leaf Structure
Its leaves are alternate and pinnately compound, with a slender, green axis tinged with reddish tones. Each leaf holds 6 to 12 pairs of leaflets on short stalks, with leaflets rounded at both ends.
Agricultural Use
This species is commonly used as a shade tree in cocoa, coffee, and tea plantations.
Cultural Significance in Thailand
In Thailand, it is the designated provincial tree of Chaiyaphum Province, and several locations across the country are named after this tree.
Chemical Composition
This plant has medicinal value and contains a chemical compound called barakol.
Edible Parts Preparation
Its leaves, tender pods, and seeds are edible, but they require pre-boiling before consumption, and the boiling water must be discarded.
Culinary Use in Thai and Burmese Cuisine
These edible parts are used in both Burmese and Thai cuisine; one well-known Thai preparation made with it is kaeng khilek (Thai: แกงขี้เหล็ก).
Traditional Burmese Cultural Use
In traditional Burmese culture, Burmese families pick Siamese cassia buds on the full moon day of Tazaungmon, and prepare them in a salad called mezali phu thoke (မယ်ဇလီဖူးသုပ်) or in a soup.
Agroforestry Uses
Other non-edible uses for the species include use as a fodder plant, incorporation into intercropping systems, and planting for windbreaks and shelter belts.
Hardwood Ornamental Use
As a hardwood, it is used for decorative ornamentation on instruments including ukuleles and guitars, and for other decorative products.
Wood Common Name Origin
When used for this purpose, it is often called pheasantwood or polohala, a name inspired by the similarity of the wood's grain to pheasant feathers.
Chinese Furniture Use
It is sometimes used in Chinese furniture, where it is known as jichimu, and is used interchangeably with wood from Ormosia species.
Medicinal Mechanism
Scientific studies have confirmed its medicinal potential, which comes primarily from the anxiolytic properties of its main active chemical, barakol.
Medicinal Products and Uses
It is sold in Asian pharmacies, most commonly as a sleep aid, but also to treat constipation and used as a hair balm.
