biology zoology blog benno meyer rochow plant gravity

Grappling with Gravity

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”? —>—>