Non-native Phragmites subspecies on the left, native Phragmites subspecies on the right. Photo by Mary Meyer, U of MN.
Stand of non-native Phragmites. Photo by S. Kelly Kearns.
Appearance: Phragmites australis subsp. australis is a non-native subspecies of common reed. The native common reed is Phragmites australis subsp. americanus. Both subspecies are perennial wetland grasses and both are present in Minnesota. The invasive subspecies can grow over 12 feet high in dense stands.
Leaf blades: Stems of native subspecies are smooth, stems of invasive subspecies are ribbed. Leaf sheath of the native is easy to remove or falls off; invasive is difficult to remove.
Flowers: Flower head of native species is sparse, flower head of invasive subspecies is dense.
Roots: Deep and dense network of roots and rhizomes.
For help distinguishing native vs invasive Phragmites see: Mistaken Identity - Invasive Plants and their Native Look-Alikes