Genus Astomum
 The species of the Genus Astomum are minute, simple or branching plants, living in matted tufts on the ground.
The species of the Genus Astomum are minute, simple or branching plants, living in matted tufts on the ground.The leaves are lance-shaped, tufted and curling toward the apex of the stems.
The spore-cases are erect and symmetrical on a short pedicel and are immersed in the leaves. They have distinctly formed, beaked lids, which are not easily detached. There are no teeth.
The generic name Astomum, from; privative, without, and; a mouth, was given because when first known this moss was supposed to have no lid.
There are seventeen species in all.
Astomum Sullivantii Moss