Scientific Name : Senna surattensis (Burm. f.) H. S. Irwin & Barneby
Common Name : Sunshine Tree
Chinese Name : 黃槐決明, 黃槐
Family : CAESALPINIACEAE
Local distribution status : Exotic species
| Origins | Tropical Asia, Australia and the Pacific. |
|---|---|
| Applications | The Sunshine Tree is a common horticultural greenery, often used as street trees and hedges. It is a small tree that does not occupy a large area. It blooms almost all year round, with bright golden flowers which are resplendent and eye-catching. It has low-maintenance needs, strong adaptability, and a high resistance to drought and cold. However, it is less tolerant to wind. Its branches and trunks are relatively fragile, and easily break or tilt after strong winds. Therefore, it is suitable to be planted in sheltered places. Its flowers, fruits and leaves can be used as Chinese herbal medicines, exhibiting the function of heat clearance. |
| Ecology | In Hong Kong, Sunshine Tree is the host plant of the two common butterflies under the genus Catopsilia (Hübner, 1819) - Lemon Emigrant (Catopsilia pomona (Fabricius, 1775)) and Mottled Emigrant (Catopsilia pyranthe (Linnaeus, 1758)). Interestingly, the wings of these adult butterflies and the petals of Sunshine Tree share the same colour tone as yellow. |
| Sunshine Tree can “sleep” | Same as many leguminous plants, the leaves of Sunshine Tree will “sleep”. The leaves will close before nightfall, and reopen to photosynthesize at dawn. This phenomenon is called “Nyctinasty” biologically, but further scientific studies are required to investigate the mechanisms. |
| Growing habit | Evergreen tree. |
|---|---|
| Height | To 7 m. |
| Stems | Bark of trunk greyish brown, smooth. Branching many, longitudinally ridged. |
| Leaves | Pinnate. Leaflets 7 to 9 pairs, oblong, elliptic to ovate. Apex rounded, slightly emarginate. Rachis and petiole flattened, tetragonal. |
| Flowers | Yellow. Inflorescences axillary, flowers about 10. Petals 5, ovate to obovate, subequal. Sepals 5, ovate-orbicular, unequal. |
| Fruits | Legume strap-shaped, flattened, dehiscent, apex long slender beaked. Fruiting valves papery, fruiting pedicels conspicuous. With 10 to 12 seeds. |
| Seeds | Oblong, flattened, glossy. |
| Flowering period | All year around. |
| Fruiting period | All year around. |
Scientific name above is based on Hong Kong Herbarium website : https://www.herbarium.gov.hk/en/hk-plant-database/plant-detail/index.html?pType=species&oID=8364
Scientific names from other databases
― Flora of China : Senna surattensis (N. L. Burman) H. S. Irwin & Barneby
― Plants of the World Online : Senna surattensis (Burm.f.) H.S.Irwin & Barneby