The leaf sheaths around the stems can be very hairy to woolly.

Stems, leaf sheaths and often leaves are covered with black spines up to 6 cm long.

Some flowers may also be produced on short stems that barely emerge from the leaf sheaths later in the season.

They bore in the stems and leaf sheaths of their host plant.

Infections can also occur on the leaf sheaths and ears.

The eggs are thrust in a straight line generally along the mid-region of the leaf sheath.

A minimum 20x hand lens is required to observe it on the inside of the leaf sheath.

The leaf sheaths are pale green or may have a dark reddish-purple tinge.

Spot may also appear on the leaf sheaths, necks and heads of the plant.

The leaf sheath is rounded, smooth, and shorter than internodes.