As others have mentioned, this is good.
The length of the inflorescence is determined by the plant in response to environmental conditions (light, nutrients) so it can vary from plant to plant and tank to tank. The most activity I have seen on one plant [Echinodorus bleherae which is what this is] was four of these--appearing almost simultaneously--and two of them branching, one even into three sub-stems.
It is unlikely they will flower when the main plant is being grown submersed. I did once have the inflorescence of E. major flower, which is also very rare, but never an E. bleherae. Adventitious plants will form at each of the nodes as someone said. You will have two distinct plants at each node.
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