Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical woody species, for example in Dipteryx odorata. Semi-deciduous or semi-evergreen may also describe some trees, bushes or plants that normally only lose part of their foliage in autumn/winter or during the dry season, but might lose all their leaves in a manner similar to deciduous trees in an especially cold autumn/winter or severe dry season (drought).
The term is also used to indicate a forest that consists of a mixture of deciduous and evergreen woody plants in the tropics and semi-tropics. It differs in its use from a mixed forest, a term usually applied to woods that contain both conifers and broad-leaved trees. Such forests receive less than 150 cm rainfall. Saagwan, Saal, Bamboo etc. are found in these forests.