A version of this story appears in the February 2017 issue of National Geographic magazine. Citrus, in many ways, stands alone. So many cultivated species have come from so few primary ancestors.

However, plotting the citrus family tree, with its many intersections, is difficult thanks to a scant fossil record. "Fruits don't make good fossils. There are leaf impressions and wood but ...

The mandarin orange is apparently the most grown among citrus fruits in India ... like standing under an amaltas tree in full ...