Cryptomeria japonica 'Ryoku Gyoku' is a irregular-globose, extremely slow-growing selection of Japanese cedar with dense, miniature dark-green awl-like foliage that will assume a light-bronzy cast in winter in colder climates. After 10 years of growth, a mature specimen will measure, at best 8 to 10 inches (20 - 25 cm) tall and wide, an annual growth rate averaging less than 1 inch (2.5 cm).
This cultivar originated as a witch's broom found in the late 1990s on a containerized specimen of C. japonica 'Tansu' by Edsal Wood of Aurora, Oregon, USA at his nursery, Bonsai Village. The cultivar names loosely translates into "Jade Ball" in the Japanese language.