At the root of numerical cognition: the case of pea plants.

Quantity discrimination is defined as the knowledge of quantities and their relationships, which is linked to the organism’s ability to adapt to an unpredictable environment. This ability is an adaptive and innate cognitive trait of animals. Here, we investigated whether plants present sensitivity to the element quantity and if so, how sophisticated is such ability in relation to those observed in different animal species. We characterized the movement of P. sativum plants in the presence of the either equal (2 vs. 2) or unequal (1 vs. 3) quantity of supports in the environment using three-dimensional (3D) kinematical analysis. Results showed that plants are able to perceive elements in the environment and estimate their quantity. This evidence, even if rudimentary, has shown that plants present quantity-related abilities that may underlie the enhancement of adaptive decision-making strategies.