Phragmites australis
Phragmites australis ssp. australis is an aggressively invasive non-native grass that is native to Malaysia which has widely invaded the eastern United States and Canada. Each Phragmites stalk holds hundreds of spikelets that each contain between three and nine florets.
The reason Phragmites can spread rapidly is its two reproduction pathways; by seed and by dispersed root (rhizome) fragments that are carried by water and human activities to other ecosystems. This flexibility in reproductive dispersal makes it very mobile especially adjacent to streams and highways. Once Phragmites has established itself in an area, it quickly forms a monoculture that crowds out many other groundcover species and may even impact other species like birds who are nesting and fish habitat.