Tropisms and Nastic Movements
Tropisms are growth responses of plants that result in curvatures of plant organs toward or away from certain stimuli. Tropisms can be positive, in which case the plant will bend toward a stimulus, or negative, in which case the plant will bend away from a stimulus. Important tropisms in plants include phototropism, gravitropism, and thigmotropism.
(2002). Tropisms and Nastic Movements. Biology Reference.