Habitat
![](https://blogs.ubc.ca/biology321/files/2018/11/Hypnum.jpg)
Hypnum ciricinale is commonly found in humid coniferous forests on the bark of logs in early stages of decomposition. Sometimes also found on tree trunks and rocks.
Gametophyte
Overall Structure:
![H. circinale overall structure](https://blogs.ubc.ca/biology321/files/2012/01/Hypnum_circinale_IMGP4797-300x225.jpg)
This pleurocarpous moss creeps over the substrate. The shoots are pale, glossy and light-green in color (sometimes brownish). The leaves are falcate-secund (curved and pointing in one direction) toward the substrate.
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Leaf Structure:
![H. circinale leaf whole-mount](https://blogs.ubc.ca/biology321/files/2012/01/Hypnum-circinale-leaf-1-web-300x225.jpg)
Leaves are ovate-lanceolate, acostate, with long-attenuate apices that almost form a complete ring or circle, hence the specific epithet given to this species.
![hypnum_leaf_margin](https://blogs.ubc.ca/biology321/files/2012/01/hypnum_leaf_margin-300x149.jpg)
The leaf margin has many small teeth near the leaf tip.
Stem:
Sporophyte
![H. circinale sporangium with peristome teeth](https://blogs.ubc.ca/biology321/files/2012/01/hypnum-sporophyte-dehisced1_edited-1-web-300x240.jpg)
Once the operculum has fallen off the peristome teeth are revealed. This moss has two rows of teeth: the outer row (exostome) which are yellowish and broken off in this picture and the inner row (endostome) which are thinner.