Aqua sobriquet said:
I didn't misinterpret the data, I just didn't see how this could relate to mosses which are so very different and don't have roots for example! We'll have to agree to disagree on this one Clive! 😀 If you have any Moss specific info relating to the problem let me know though 😉
The fact of being unable to see how the data relates to mosses directly contributes to misinterpretation. Why have you concluded that a moss is so much different than other wetland plants just because mosses lack roots? Why is having roots a more important factor to similarity than actually being aquatic, and having genes specifically dedicated to life underwater? By this logic hairgrass is more similar to the rye-grass in your lawn than it is to cryptocoryne simply because it is grass-like.
The article you linked to specifically shows how radically different two Rumex species behave even though they are both Rumex, and even though they both have roots. The author has demonstrated how much more important their individual responses to ethylene are, which contributes to their radical differences in tolerance to being flooded. That makes R. palustris similar to moss and makes R. acetosa completely dissimilar, regardless of roots.
Within the context of stem elongation, root morphology is not altogether relevant. How the plant responds to ethylene buildup in the tissues is the salient feature, so that's what we need to look at. In other types of behavioral investigations roots will be relevant, but not in this case. Aquatic plants share many more features in common with each other than with terrestrial plants, even if they look radically different, because the aquatic environment is so special that how the plant functions and solves the riddle of water is a more important, and is a more telling similarity.
It's OK if you disagree mate. No worries at all. I'm only commenting to help other readers get a clearer picture. 99% of aquatic plant websites in the world tell their users to add more light to get their plants to stop elongation. So people follow this advice because it seems reasonable and later, pandemonium breaks loose in their tanks. If, by some coincidence the plant does stop the elongation, other problems in the tank simply begin to mount.
Cheers,
