Citrus ryukyuensis

Citrus ryukyuensis, also known as the tanibuta (Okinawan: タニブター, romanized: tanibutā, lit. 'big seed'), is a newly characterized wild citrus species native to the Ryukyus and adjacent islands, most closely related to the mainland mandarin orange, C. reticulata. As with other citrus, it is a member of the Rutaceae family. The Ryukyu and mainland species have diverged for more than 2 million years, and unlike the mainland mandarin, the Ryukyu mandarin reproduces sexually. Its hybridization with the mainland species has given rise to the unique mandarin hybrids of the islands.