An orangeâ€”specifically, the sweet orangeâ€”is the citrus Citrus Ã—sinensis (syn. Citrus aurantium L. var. dulcis L., or Citrus aurantium Risso) and its fruit. The orange is a hybrid of ancient cultivated origin, possibly between pomelo (Citrus maxima) and tangerine (Citrus reticulata). It is a small flowering tree growing to about 10 m tall with evergreen leaves, which are arranged alternately, of ovate shape with crenulate margins and 4â€“10 cm long. The orange fruit is a hesperidium, a type of berry. Oranges originated in Southeast Asia. The fruit of Citrus sinensis is called sweet orange to distinguish it from Citrus aurantium, the bitter orange. The name is thought to ultimately derive from the Dravidian and Tamil word for the orange tree, with its final form developing after passing through numerous intermediate languages. In a number of languages, it is known as a "Chinese apple" (e.g. Dutch Sinaasappel, "China's apple"). Peel, also known as rind or skin, is the outer protective layer of a fruit or vegetable which could be peeled off. The rind is usually the botanical exocarp, but the term exocarp does also include the hard cases of nuts, which are not named peels since they are not peeled off by hand or peeler, but rather shells because of their hardiness. A fruit with a thick peel, such as a citrus fruit, is called a hesperidium. In hesperidiums, the inner layer (also called albedo or, among non-botanists, pith) is peeled off together with the outer layer (also called zest), and together they are called the peel. The zest and albedo, respectively, are the exocarp and the mesocarp. The juicy layer inside the peel (containing the seeds) is the endocarp. Depending on the thickness and taste, fruit peel is sometimes eaten as part of the fruit, such as with apples. In some cases the peel is unpleasant or inedible, in which case it is removed and discarded, such as with bananas or grapefruits. The peel of some fruits, for example pomegranate high in tannins and other polyphenols, is employed in production of dyes. The peel of citrus fruits is bitter and generally not eaten raw, but may be used in cooking, e.g. chenpi. The outermost, colored part of the peel is called the zest, which can be scraped off and used for its tangy flavor. The fleshy white part of the peel, bitter when raw in most species, is used as succade or is prepared with sugar to make marmalade or fruit soup.