AppearancePhragmites australis is a tall, perennial grass that can grow to heights of 15 ft. (4.6 m) or more. Broad, pointed leaves arise from thick, vertical stalks. Foliage Leaves are 6-23.6 in. (15-60 cm) long, 0.4-2.4 in. (1-6 cm) wide, flat and glabrous. Flowers The flower heads are dense, fluffy, gray or purple in color and 5.9-15.7 in. (15-40 cm) long. Flowering occurs from July to October. Fruit The seeds are brown, light weight, and about 0.3 in. (8 mm) long. In the fall the plant turns brown, and the inflorescences persist throughout the winter. Ecological ThreatPhragmites australis is usually found in dense thickets growing in or near shallow water. These thickets displace native wetlands plants, alter hydrology and block sunlight to the aquatic community. It is native to Eurasia and Africa. Native Phragmites do occur in the United States and they are sometimes very difficult to distinguish from the exotics.