The tangerine (Citrus tangerina) is an orange-colored citrus fruit that is closely related to, or possibly a type of, mandarin orange (Citrus reticulata). The name was first used for fruit coming from Tangier, Morocco, described as a mandarin variety. Under the Tanaka classification system, Citrus tangerina is considered a separate species. Under the Swingle system, tangerines are considered to be a group of mandarin (C. reticulata) varieties. While tangerines genetically resemble mandarins, the genetics are still not thoroughly studied. The term is currently applied to any reddish-orange mandarin (and, in some jurisdictions, mandarin-like hybrids, including some tangors), but the term "tangerine" may yet acquire a definite genetic meaning.