This is a discussion on how do I propagate amazon sword plant. within the Beginner Planted Aquarium forums, part of the Beginner Freshwater Aquarium category; -->
Hi all I bought amazon sword plant it is doing amazing,(sending a stem thing to the surface) and I wish I had two but ...
You can divide the rhizome but unless the plant is quite large I would not risk it.
The inflorescence will produce adventitious plants; once the leaves are several and about 3 inches in length [I'm assuming this is the common sword, Echinodorus bleherae] with some new roots an inch or more, you can remove the plant by carefully pulling it downward along the inflorescence (towards the base) and planting it. It will take time to reach the size of the parent plant, several months usually.
OOOOHHHHH so it already broke the surface and should I cut it or just let it flower
Leave it alone. It is very rare for an Echinodorus grown submersed to flower, but adventitious plants will be produced from the nodes along the stem. Echinodorus will flower if grown emersed as a bog or marsh plant. If you read the plant's profile this is all explained. Click on the shaded name, Echinodorus bleherae.