This is the winter bud of Usunoki (Kakuminosunoki). So far I have found only one in Kameyama Park. The tree has formed winter buds and its branches are turning red. I learned of its existence when I noticed the pretty red fruits this fall. The red leaves were also beautiful in late fall. Next year, I plan to periodically observe the plant from budburst to leaf fall. I heard that it got its name from the shape of the fruit. The fruit of this tree is slightly angular and has a concave tip, making it look like a mortar.