Rhizomnium glabrescens

Rhizomnium glabrescens, Male Gametophytes

This is a very common moss species on the tops of logs in lowland forests of the Pacific Northwest.  It comes in two varieties of gametophytes, the male gametophytes which produce sperm and have the splash-aiming arrangement of leaves around the top, and female gametophytes, usually seen with attached sporophytes.