Wavy hair-grass is a slender meadow grass and is one of the most common grasses in Finland. Its narrow, thread-like leaves form round tussocks. The straw of wavy hair-grass grows approximately half a metre high and its scattered, straggly-branched panicle is located at the top of the straw. The species flowers between June and July.

Wavy hair-grass prefers bright habitats like mesic and sub-xeric heath forests, clear-cut areas and meadows. Its area of distribution covers Europe (excluding its most eastern parts), Japan, Greenland, the eastern parts of North America and the southern parts of South America.

In the wintertime wavy hair-grass is an important food plant for the reindeer.

As a common species wavy hair-grass requires no conservation measures to secure its occurrence.