Abstract: Field measurements have demonstrated that sunlight polarized during a first surface reflection by shiny leaves dominates the optical polarization of the light reflected by shiny-leafed plant canopies having approximately spherical leaf angle probability density functions (“Leaf Angle Distributions” – LAD). Yet for other canopies – specifically those without shiny leaves and/or spherical LADs – potential sources of optically polarized light may not always be obvious. Here we identify possible …