The stilt mangrove (Rhizophora spp.) fruits contain a single seed which develops on the tree into a seedling with a long green hypocotyl called a propagule. As it falls, the propagule is planted in the loose substrate near the tree it came from, or further if it is carried away by the sea, and gives rise to a new mangrove plant like the one in the photo. Stilt mangrove propagules can live for over a year in seawater and float for over a hundred days.