Phragmites aka Phrag aka European Common Reed

[ShadowHM]

For a different opinion:

http://www.njaudubon.org/SectionConserva...inion.aspx

I suspect that the linked article is referring to the native version, not the invader.

From the first link I gave:

Identifying Invasive Phragmites

One factor making the identification of invasive Phragmites difficult is the existence of a closely related native subspecies. Generally, native Phragmites does not grow as tall as the invasive plant and does not out-compete other native species. A number of characteristics of the plant can be useful in distinguishing between the native variety and invasive Phragmites. The following information can help in identifying invasive Phragmites.

Invasive Phragmites:

grows in stands that can be extremely dense with as many as 200 stems per square metre;
can grow so densely that it crowds out other species;
can reach heights of up to 5 metres (15 feet), and
has stems that are tan or beige in colour with blue-green leaves and large, dense seedheads.


Native Phragmites:

grows in stands that are usually not as dense as the invasive plant;
well-established stands are frequently mixed with other plants; and
usually has more reddish-brown stems, yellow-green leaves and smaller, sparser seedheads.