Kingdom: Plantae
Phylum: Bryophyta
Class: Polytrichopsida (Hair Mosses)

Polytrichopsida is a class of mosses containing about 23 genera, and are often considered to be pioneer plants. Species in this class are acrocarpous meaning they have clustered upright stems with the reproductive parts borne at the tip of a stem. They have worldwide distribution on every continent typically occurring on acidic, exposed, and nutrient-poor soils. Although polytrichopsida is smaller class than Bryopsida, it still displays great diversity among species which range from miniature plants up to the large Dawsonia superba, which can grow as tall as 500mm.