Puffgrass

This enormous, green grass grows up to 22 feet (6.7 meters) tall. The asymmetrical stalks grow in thin clumps that are light and frail.

When mature, the end of the stem eventually transforms into a small, green puff.

During the late autumn, it produces lots of pollen, but it does not cause any allergic reactions, and after flowering, it is left with excessive amounts of tiny grains.