Camellia japonica

Family: Theaceae
English: Japanese camellia or simply camellia
Japanese: ヤブツバキ (Yabu tsubaki) or リンゴツバキ (Ringo tsubaki) or ヤクシマツバキ (Yakushima tsubaki)

The camellia is a culturally significant flower in Japan. You may know that the oil is used in hair products. The flowers fall intact from wild varieties, in contrast to sasanqua flowers. The Yakuhisma variety is known for large seed pods that can swel to the size of a typical apple, and as the color changes from green to red, they look like apples hanging on the tree. However, the size is entirely due to the thick skin. The skin has evolved into a hard, thick rind in response to weevils that have, in turn, evolved proboscises that can be up to 2cm long to deposit eggs inside the camellia seed pods.

References:
九州野山の花 片野田逸朗,2004：南方新社.
米倉浩司・梶田忠 (2003-)　「BG Plants 和名－学名インデックス」（YList），http://ylist.info（ 2016年9月15日）.