How ivy hangs on
German scientists studying ivy (Hedera helix) have shown that its roots stick to things in four distinct steps:
- Initial contact
- Roots grow onto the surface, and lignify (get tougher).
- Roots produce glue, which seems to react with the surface.
- Tiny root hairs anchor the root to any minute crevices in the surface.
There’s quite a bit more about how the root hairs manage the final step. Their walls are structured so that, as a root hair dies and dries out, it coils up, catching on any irregularities and pulling the root in to the surface. If you’ve got access to the paper, have a look at the electron micrographs (unfortunately I can’t put them up here).
English ivy’s climbing secrets revealed by scientists, BBC News, 28 May 2010
Melzer, B. et al. (2010) The attachment strategy of English ivy: a complex mechanism acting on several hierarchical levels, Interface, doi: 10.1098/ rsif.2010.0140