For what it's worth, I looked at a whole bunch of water-based crops like lotus and similar root/rhizome plants in Australia as part of research for Lands of Red and Gold. The conclusion I quickly reached was that they were suitable as supplemental crops but not as staple crops.
The strikes against them are several, and not ones which are easily changed by artificial selection.
Firstly, they're very labour-intensive. Which is tolerable for an occasional gathering as a delicacy or the like, but a great disincentive for a staple. Less likely to start agriculture, and more likely to be abandoned in favour of less labour-intensive crops even if domesticated or introduced.
Secondly, they really do not store well. Being watery crops they're designed to have the protection of water to keep them safe from moulds and rots. Take them out of that environment and they're likely to turn bad very quickly. Again, not something easily bred out through artificial selection. (Edit: just saw the post about longer-storing wild ones. That's a good start, but it really needs to be year-round storage for a staple crop.)
Thirdly, they depend on, well, water. A lot of water. No water, no crops. Not a good thing in a country like Australia, where rainfall is unpredictable at the best of times. Even if limited to cultivation along rivers... well, rivers in Oz flood a hell of a lot. Doesn't augure well for a lotus crop.
There are other issues too, but those are probably the biggest ones.
The strikes against them are several, and not ones which are easily changed by artificial selection.
Firstly, they're very labour-intensive. Which is tolerable for an occasional gathering as a delicacy or the like, but a great disincentive for a staple. Less likely to start agriculture, and more likely to be abandoned in favour of less labour-intensive crops even if domesticated or introduced.
Secondly, they really do not store well. Being watery crops they're designed to have the protection of water to keep them safe from moulds and rots. Take them out of that environment and they're likely to turn bad very quickly. Again, not something easily bred out through artificial selection. (Edit: just saw the post about longer-storing wild ones. That's a good start, but it really needs to be year-round storage for a staple crop.)
Thirdly, they depend on, well, water. A lot of water. No water, no crops. Not a good thing in a country like Australia, where rainfall is unpredictable at the best of times. Even if limited to cultivation along rivers... well, rivers in Oz flood a hell of a lot. Doesn't augure well for a lotus crop.
There are other issues too, but those are probably the biggest ones.