This flower is called Sansyu-yu (山茱萸) in Japanese, and it is one of species of dogwood . The plant is a flowering tree, usually 5 feet to 20 feet tall as shown in below. Sansyu-yu is also one of flowers that blooms in early spring as same as Japanese plum blossoms.
Japanese cornel, called "Sansyu-yu" in Japanese, bloomed like split opened or burst from a husk.
The plant is a species of dogwood family and native to China, and came to Japan via Korea peninsula at early 18the century as a medicinal plant.
It is said that the seeds harvested from the plant are to be effective in treating infertility and poor circulation.
The bud of this plant is wrapped in a hard husk shown in the image below.
