According to new approaches to treatment of reeds, there exist a few reed species world-wide. The most conspicuous among them is giant reed, the largest and most invasive species of Mediterranean origin. According to the Russian authority on grasses, N.N. Tzvelev, it is now widespread in Russia along with P. australis, with which it does not cross even when both grow close together. Giant reed is characterized by broad leaves (2.5-4.0 cm wide).