An Arcyria sp. but not possible to give you a species without doing the microscopy. Closer photos will also be of great help when attempting a complete identification. We need to see the length of the stem which is only a mm or so tall, the shape and patterns on the calyculus (cup above stem) and the decorations on the capillitium and the spores. The last two cannot be seen unless a microscope is used. Did you by any chance collect a specimen?