Senna siamea (yellow cassia).
Abstract S. siamea is indigenous to southern India, Sri Lanka, Malaysia, Cambodia, Thailand and Myanmar, although it has been introduced widely into many states of India and also many countries in tropical Africa. As well as producing a good quality timber, often used for marquetry and inlay work due to its fine figure, the tree is used for erosion control planting, windbreaks, as a host for sandalwood (Santalum album), and as a nurse crop for Swietenia mahogani, to reduce borer attack. It is a common shade tree in Philippine towns and cities. It has been used to revegetate degraded agricultural land and is planted in taungya systems. It may be used as a shade tree for coffee (Heinsleigh and Holaway, 1988).It is one of the chief afforestation species in the dry zone of the Indian states of Andhra Pradesh, Tamil Nadu and Karnataka. The major disadvantage of the species is that it has a shallow root system, which make it susceptible to strong winds. Wood sawdust can cause irritation when in contact with the skin. Trials for timber plantations have been recommended (Gutteridge, 1997; Sosef et al., 1998), particularly as S. siamea could combine timber production with ornamental value. Research on genetic variation to determine the extent of adaptation of various provenances would also be of value.