@@Pseudosasa japonica (Sieb.et Zucc.) Makino var. Tsutsumiana Yanagita

Kyoto Rakusai Bamboo Park
This is really funny and mysterious shaped bamboo!
As you can see, the culm looks like a joint of scallions.
That is, "Rakkyo" in Japanese means a scallion.

This is one of mutations of P. japonica.
This rhizome is also nearly the same shape as swelling in internodes.

According to Dr. Hiroshi Muroi, this was found by Yoshizo Yanagita at the garden of Mr. Toshiro Tsusumi located at Mito city in 1932.