Minute observations and theoretical framework of Darwin's studies on climbing plants

The role of movement in plants was unrecognised for a long time, due to the relative slowness of such movements by comparison with those of active animals such as insects and vertebrates, and to the difficulty with which they are distinguished from mere growth processes. Given this, the pioneer work of Darwin (On the Movements and Habits of Climbing Plants1865) is a milestone in botany. It is always cited as the beginning of any rigorous analysis of plant movement. Such a successful approach results at once from Darwin's broad knowledge of natural history, his use of numerous direct observations and simple experiments, but also from his own talent, which compensated for technical gaps in several instances. His use of metaphorical descriptions was a response to the lack of a firm theoretical background. It facilitated a preliminary classification of plant movement and a comparison of observations. Perhaps his most fruitful metaphors were those drawn from economic concepts, such as division of labour. Darwin's legacy in plant physiology is impressive, as even the most recent biophysical interpretations of climbing plants (e.g. tendril perversion) take place inside the framework he constructed.