This form of vivax grew as a sport of Phyllostachys vivax 'Aureocaulis' when we propagated that bamboo from rhizome. Its coloration does seem fairly stable. It is essentially a "yellow groove" form of vivax--a yellow stripe occurring primarily on the sulcus of the culm. Mature height should be 35 to 45 ft. (possibly much taller) with an expected culm diameter of 3" to 5". Hardiness is listed at -9° F by the American Bamboo Society. Possibly a little more cold hardy than regular P. vivax but we don't get cold enough in Portland, Oregon to give it a thorough test.