Keep in mind as well that it is highly unlikely that black bamboo seeds will produce black offspring, the greatest likelihood is that the next generation will all be green - unless you win the genetic lottery which is certainly possible but very unlikely.
Brad Salmon, zone 5b/6 Southern Indiana
Winters -20 to -25C. Summers 30 to 35C , humid. 115 cm annual precipitation, frost free from May through early October. 259.3 meters elevation. Growing 150+ species. http://www.needmorebamboo.com/