Today in 1862, Charles Darwin wrote to Asa Gray, a botanist at Harvard University: “I should like to try a few experiments on your Tendrils; I wonder what would be good & easy plant to raise in pot.”
With this letter, Darwin responded to a short paper by Gray describing the sensitivity of growing plant tendrils to touch, “Note on the coiling of tendrils” published in the Proceedings of the American Academy of Arts and Sciences.
Gray sent Darwin seeds of two climbing plants: the bur cucumber (Sicyos angulatus) and wild mock cucumber (Echinocystis lobata), which Darwin could plant in the spring to begin his observations. Gray did warn, however, that whilst the mock cucumber was “genteel”, the bur cucumber was “as nasty and troublesome” as any plant he knew, so Darwin would have to watch it closely.
After weeks of watching young tendrils slowly corkscrew their way toward the sun, Charles Darwin set about inventing a system for making botanic motion visible to the naked eye.
Darwin’s observations became the basis of how we now understand the physiology and behavior of climbing plants. Beyond the climbers, Darwin laid the foundations for the study of plant behavior and intelligence. Darwin’s work showed that the centuries-old presumption “that animals moved & plants did not” was entirely wrong, a matter of perception that could be overcome.
Source: Natalie Lawrence, “Spontaneous Revolutions”: Darwin’s Diagrams of Plant Movement, The Public Domain Review, October 26, 2022