Wild oat seeds turn and plant themselves into the ground. I'm
trying to find a better explanation for this than to simply say
these are hygroscopic movements. The oat stem has a 90 degree
bend in it, causing the seed to move, almost walk, with each
rotation. Has anyone looked at this adaptation? It's very well
known, but I find no discussion of it in the botany texts I have.
Can someone explain this behavior and give me a reference.
I have a couple of other related questions I might as well ask at
the same time: Is there a better explanation for thigmotropism
than that the cells that make contact shorten, while those on the
outside elongate? Does auxin cause gravitropism in roots, or are
other agents involved?
Finally, the six hour BBC program "The Private Life of Plants"
just made its North American debut on Turner Broadcasting and in
Canada (Access in Alberta at least). It contains spectacular
time-lapse footage as the producers tried to put viewers in the
time frame of plants, but it also missed a few opportunities,
e.g. explaining how a tree grows. How useful will it be for
teaching university level courses?