It may root at stem nodes which become buried in wet substrate.

The shaggy hairs on the stem nodes may be up to 8 millimeters long.

The stem nodes are slightly swollen and look somewhat like "knots," thus its common name, knotweed.

It creeps along the ground, spreading by sending down roots at the stem nodes.

The branches are covered in prickles and there are spines up to 1.3 centimeters long at stem nodes.

The stem nodes are covered with a sheath that is marked with a black band and has dark teeth with white edges.

Partly emerging from the foliage, they arise from two- to three-year-old stem nodes.

The prostrate plants reproduce by seed and by sending roots from stem nodes.

It sometimes roots at stem nodes that become buried in moist substrate, and forms dense stands.

This perennial grass has decumbent stems that spread along the ground and root where stem nodes come in contact with the substrate.