Utricularia leaves, stems and roots?

[witzelsucht]

I was talking to someone about Utricularia who asked the (very basic) question - "are the traps modified roots?" and I had to admit I didn't know. After trying to research the question with some of my fairly basic references I am even more confused.

Is it safe to say that the above ground non flowering parts are "leaves"?

The word stolon is used a lot when describing utrics. I'm under the impression that a stolon is a modified stem similar to a rhizome - is that true?

Now I'm not even sure if Utricularia have roots (at least from a developmental point of view). Are all of the below ground parts considered "stolons"? Anyone more botanically inclined willing to shed some light on this?

Thanks,
Rich

[rsivertsen]

The answer is revealed in their development from seedling stage. Their seeds germinate with a hypocotyl, which is the embryonic root, but that eventually shrivels up and dies. The same is true with Aldrovanda, another rootless aquatic CP, but belonging to the Droseracea family and is the VFT's closest living relative.

So that, (to answer your question), the traps are indeed modified leaf parts.

Strawberry plants have stolons, which are not at all part of a root system, but a vegetative means, (a modified stem) of producing another plant. Many other plants produce stolons.

- Rich

[Dave Evans]

Utricularia have managed to turn themselves just about all around. The leaves are underground suction traps, the green things that collect sunlight are actually stolons, which are highly modified stems, to say the least. And the white thread-like structures running parallel to the ground are the main stems. Then there are highly modified stems, again, which act as roots called rhizoids.

Just about the only thing on these plants that follow traditional plant morphology are the flowers! They are still used for attracting pollinators and making seeds.

[witzelsucht]

Thanks Rich and Dave for answering my question. No wonder I was confused! I can take solace in the fact that I was no more confused than the plants themselves. Fascinating stuff.