Widely distributed in the Northern Hemisphere, it grows in mountainous areas in the southern part of its range.

It is characterized by a clearly visible terminal bud in the middle part of the head and usually a dark brown stem.

[4] It is also distributed in North America,[6] extending south into mountainous areas in Colorado[7] and California.

The other two to three branches are drooping and have highly variable lengths[5][9] (usually finer, lighter, and slightly longer than the spreading ones).

Sphagnum angustifolium, or fine bogmoss, is also similar, but its apex bud is always hidden by the branches.

[7] Sphagnum teres has a broad trophic spectrum;[7] it occurs in eutrophic and mesotrophic peatlands,[1] as well as fens.

[9] However, these habitats are always minerotrophically fed, meaning they are nourished by waters that have previously flowed through mineral substrates.

[5] The species is tolerant of varying moisture levels and shade[1] but prefers open areas, rarely growing in thickets or sparse forests,[9] always in locations that are at least damp or wet.

[1] In the classification of plant communities in Central Europe, Sphagnum teres is characteristic of Caricion lasiocarpae.

Sphagnum teres lent its name to Sphagnion teretis Succow 1974, which is currently divided into Sphagno warnstorfii-Tomentypnion nitentis Dahl 1957 and Caricion fuscae Koch 1926.

and the section Squarrosa (Russow) Schimp..[5][6][13] This section includes medium to large-sized Sphagnum characterized by a head with a prominent terminal bud, with stem leaves that are either spreading or partially drooping, large, tongue-shaped (± rectangular), and somewhat serrated at the tip.

[15] The presence of plants exhibiting intermediate characteristics between Sphagnum teres and S. squarrosum, as well as their close genetic relationship, suggests the possibility of hybridization between these species.

On a continental scale in Europe, its resources are considered substantial (especially in Scandinavia and the Baltic countries), and it holds the status of Least-concern (LC) on the IUCN Red List.