Each process involved in the generation of plant body form and function is under the control of signals from the exogenous and/or endogenous plant environment. These controls are necessary for adequate plant adjustment to the prevailing conditions, but at the same time they impose the need for sophisticated mechanisms to achieve adequate sensitivity towards signals and stability against noise. To cope with this challenge plants use multiple signals, multiple receptors even for the same signal and interactive signal transducers with multiple targets. Here we provide an overview of this multiplicity and its functional significance.