How to recognize Aulacomnium heterostichum: This moss grows erect in shady places with many reddish brown rhizoids growing on the lower part of the stem that helps to bind the clumps of plants together and help the clump of plants to cling to the substrate. The leaves are 1 to 3.5 mm long, oblong or ovate-oblong, with tips of leaves acute to obtuse with coarse teeth easily seen in a hand lens. The single costa almost reaches the tip of the leaf. The cells, which are almost round or square in shape in most of the leaf, are bulging; they do not have the single papillae found in the other species of North American Aulacomnium. Plants may have little leaf like brood bodies growing on an extension of the stem and its tip. These little bits of plant can each grow an entire new plant if they fall off and find the right environment. The capsule is on a reddish seta and is 2-3 mm long, curved and almost erect to inclined. When dry it is furrowed. In the picture above there is a good view of the peristome with its two sets of teeth that is exposed on the top of the capsule when the operculum falls off. These teeth move when the humidity changes to allow the spores to escape when conditions are right.
Where to find Aulacomnium heterostichum: Look on soil, bark, or rocks on banks in shady places. It is usually found in drier environments than other Aulacomnium species.