The Christmas stocking mandarin began as a New Year gift from Japan
North Americans stuff mandarins into Christmas stockings thanks to Japanese immigrants in the 1880s, whose families shipped them the fruit for New Year. Trains with orange-painted boxcars later carried each harvest east. And the fruit's sweetness is borrowed: wild mandarins are bitter, and nearly every commercial one carries pomelo genes.
Citrus reticulata, whose Latin name means netted, is one of the handful of original citrus species from which most modern varieties descend, alongside the citron and the pomelo. Even the familiar sweet orange is a mandarin-pomelo hybrid. Wild mandarins evolved in a small region of South China and Vietnam, and genetic studies of the Nanling Mountains suggest two separate domestications from different wild subspecies. The northern line produced larger, redder fruit such as the satsuma; the southern gave smaller, yellower kinds including Dancy and Ponkan. Domestic types have similar sugar to wild ones but, in some cases, almost 90 times less citric acid.
Wild Nanling mandarins carry no pomelo DNA, whereas domestic ones do, in differing amounts. That creates a continuum running through tangerines and satsumas to clementines, oranges and grapefruit, and it is why taxonomists disagree: one genomic scheme would reclassify most mandarins as varieties of the bitter orange. A separate island species on Okinawa split off 2 to 3 million years ago when rising seas isolated it, and its crosses with mainland fruit yielded Japanese and Taiwanese specialities such as the Tachibana orange. Very sour types such as Cleopatra are mainly used as rootstock.
The tree reaches about 7.6 metres, carries thorns and can yield up to 79 kilograms of fruit. Its thin, loose peel is its selling point, and seedless kinds such as the satsuma can set fruit without pollination. The peel is dried as chenpi for cooking and pressed for fragrant oils. World output, lumped with tangerines and clementines, was about 50 million tonnes in 2024, with China growing just over half.
Imports of the Japanese fruit to the United States stopped during the Second World War. They returned early afterwards, but lingering hostility saw them rebranded as mandarin rather than Japanese oranges. In Vancouver, the first shipment is still welcomed with a festival pairing Santa Claus with kimono-clad dancers.
Source: Mandarin orange
