With the swords, you can just cut the runner off if you like, at the base next to the mother plant. If the runner is above water, it will flower. If below the water surface, it will grow roots and form baby plants. Also, if it flowers, and then you put back under the water, roots will grow and babies will form.
55G Filstar XP3 - 16" Fire Eel
75G Medium Planted - Filstar XP3 Low Light - Established Feb 2006