Mimosa’s internal clock
AI-generated conceptual botanical illustration of Mimosa pudica with open and folded leaflets to suggest its day/night movement. It is not a historical reconstruction, photograph, or experimental diagram. Prompt: “Educational botanical illustration, vertical 4:5. A scientifically plausible Mimosa pudica sensitive plant in a pot, several feathery compound leaves with paired leaflets, some open and some folded together to suggest daily movement. Refined museum botanical art with realistic plant detail and soft neutral twilight gradient background. No words, labels, clock symbols, people, or split-panel border. Conceptual, not an actual experiment.” Generated 2026-10-29; no external source or documentary role.
In 1729, French astronomer Jean-Jacques d’Ortous de Mairan noticed that mimosa leaves folded in the evening and opened during the day. He kept a plant in darkness, yet its leaves continued moving in a daily rhythm. This suggested that the plant had an internal clock and that the cycle was not simply an immediate response to light.