Bryophytes comprise mosses, liverworts, and hornworts.
Although usually tiny, these plants can be ecologically important because they can be very abundant in some habitats, including wetter forests.
Unlike other land plants, they lack well-developed vascular tissue for moving water and food around their bodies.
They also differ in that it is the obvious "leafy" component of their life cycle that produces the sex cells (eggs and sperm), while the spore-producing structures are small and often cryptic.
The different kinds of bryophytes differ in their spore-producing structures (the sporophytes). The sporophytes of mosses have a capsule on a wiry stem, while in liverworts the sporophyte stem is fleshy. There is no discrete capsule in hornworts; instead, the sporophyte is an erect, tapering "horn" that splits near its apex to release the spores.
There are c. 500 species of mosses (Allan Fife pers. com.) and c. 600 species of liverworts (Engel & Glenny 2008) native to New Zealand.
Engel JJ, Glenny D (2008) A Flora of the liverworts and hornworts of New Zealand. Volume 1. Missouri Botanical Garden Press, St. Louis.