Complex sentence: The culms may reach as high as 4 to 9 meters, while in China it is reported as high as 16 meters and 2.5 cm to 6 cm in diammeter with dark green internodes 22--31 cm apart.
Split into simpler sentences: The culms may reach as high as 4 to 9 meters, while in China it is reported as high as 16 meters. Mature culms grow from 2.5 cm to 6 cm in diammeter with dark green internodes 22--31 cm apart.