I tried to recall its Korean name but its could not.
I shot the ball to the water.  Still cannot remember the name.  But took a picture of it.

Now I have this in my office.   The first photo on the left is taken with close-up ring (Extension ring).

March 2000

According to TIME-LIFE Encyclopedia:

Nerium oleander and varieties (oleander)
A fast-growing plant that may reach 12 feet or more, oleander bears single or double flowers that are white, yellow, pink or red, depending on the variety, and bloom from spring throughout the summer. All parts of the plant are poisonous. Oleanders need little care, withstand heat and dryness and serve equally well as ornamental shrubs or screens.