The seeds can be simply planted to mark a spot, or can be made to point north, south, east, west, north-east, north-west, south-east, south-west, or the player's current direction. All players can see the plant indicating direction if shown. Your marker plants are temporary and are destroyed after six minutes, or when you log out. Players can use the plants to mark out paths or trails to follow. Other players might plant Marker Plants to confuse that path. However, the 10 square distance limit applies to all players planting marker seeds.