  Chemical vapor deposition (CVD) is a widely used technique to grow solid
materials with accurate control of layer thickness and composition. Under
mass-transport-limited conditions, the surface of thin films thus produced
grows in an unstable fashion, developing a typical motif that resembles the
familiar surface of a cauliflower plant. Through experiments on CVD production
of amorphous hydrogenated carbon films leading to cauliflower-like fronts, we
provide a quantitative assessment of a continuum description of CVD interface
growth. As a result, we identify non-locality, non-conservation, and randomness
as the main general mechanisms controlling the formation of these ubiquitous
shapes. We also show that the surfaces of actual cauliflower plants and
combustion fronts obey the same scaling laws, proving the validity of the
theory over seven orders of magnitude in length scales. Thus, a theoretical
justification is provided, that had remained elusive thus far, for the
remarkable similarity between the textures of surfaces found for systems that
differ widely in physical nature and typical scales.
