Bank Haircap Moss

Polytrichastrum formosum generally inhabits shaded, poor soils and humus in damp coniferous forests and cool temperate rainforests. This species is most common in Europe and grows in grasslands, lowland heaths, acidic moorlands, rocky slopes, and old buildings.

Polytrichastrum formosum is sexually dioicous, meaning the male and female reproductive structures are on separate plants. P. formosum, like all members of the Polytrichaceae family, is an acrocarpous or cushion moss with reproductive structures borne at the terminus of the gametophyte stem. The perichaetial leaves surrounding the archegonia (female reproductive structure) resembles the other stem leaves besides being longer. The antheridia (male reproductive structure) are at the apex of the male gametophyte in a cup-like structure formed by perigonial leaves which are modified stem leaves. Sperm is produced in the antheridia via mitosis, and when mature they are released from the antheridia by raindrops splashing onto the cup. Sperm can be dispersed up to one meter from the male, and if they successfully reach an archegonia, the egg will be fertilized and grow into a diploid sporophyte.