In our pond, we built a tiny island and surrounded it with planks of wood to stop it eroding away. This moss was clinging to the planks. It was on the north side of the island, which is interesting because I read once that moss grows on the north side of tree trunks. This is a thread-moss. The capillary thread-moss fruits with drooping green capsules on the end of red stems, called setae. The foliage is green feathery fronds.