Water uptake rates

[ScottMcC]

I had another thought related to the discussion yesterday about root rot.

I've noticed that of my plants in s/h, some tend to suck up water far faster than others, even of similar size. Since water is available essentially as fast as the plant wants it, this would seem to indicate that some of the plants are indeed able to take up water more quickly.

now obviously there are several explanations for this phenomenon. for instance, a plant with more roots is going to be able to absorb more water, just because there's more surface area. and clearly, a plant that loses a lot of water through its leaves is going to need to take up more water to make up for this. same goes for a plant that is rapidly growing.

anyway, I think that plants of different genera are also able to take up water at different rates, solely based on intrinsic properties of the roots themselves. for instance, my oncidiums suck up water like it's nobody's business, and need to be watered every 3 days or so. I think the fine, filamentous roots are just adapted to have a very high rate of water uptake. my phals, on the other hand, can make it 1.5 weeks, and I think that this reflects a slower maximum uptake rate.

again, no data to back up these thoughts, but I'd love to hear peoples opinions, and if they do have data, even better.