A problem for plants
There can be no doubt that seedlings know that their roots have to grow down and their stems upward. This awareness of gravity seems to be maintained even in older plants, for if a young tree was lying flat on the ground (perhaps as a result of a storm), but with its roots still anchored in the soil, its tip would slowly bend upward in the months to come. Animals possess gravity receptors, statocysts, ear-stones; if they lack them they use their eyes and perceive the light from above, but plants? Where are their gravity sensors and where are their “eyes”? —>—>
A nervous system in plants?
During the time I worked for the educational TV channel “NDR Das Dritte” and produced a film on carnivorous plants with the title “Pflanzen, die von Tieren leben” (Plants that live off animals), I was of course aware of Charles Darwin’s inspiring and careful studies, published in 1875, on what was then called “insectivorous plants”. I also knew of the experiments by one of the scientific giants of India, namely Sir Jagadish Chandra Bose, who in 1926 had unequivocally shown that plants not only generate action potentials similar to those known from the nervous systems of animals, but that these plants transmitted the electrical impulse over considerable distances via their vascular bundles (of which as we now know, the phloem plays the part of a “nerve”). However, a great deal more information especially on how those sensitive plant species like the Venus flytrap Dionaea muscipula, sundews of the genus Drosera, or Mimosa spp., etc. react physiologically to mechanical or thermal stimulation is now available than it was at the time when I produced my film. —>—>
The Lichen’s Paradise on Earth: Antarctica
Lichens? Most people if asked what they associate with the word ‘lichens’ may scratch their heads and come up with nothing. Some, however, will think of packing material and decoration used by florists in flower shops. And then there are those, who think of reindeer and other Arctic grazers like musk oxen, snow hare, etc. But I’m thinking of Antarctica as the “continent of the lichen”, a continent without grazers that could harm the lichen. —>—>