The radiative transfer equation for photons interacting with the phytoelements (primarily leaves) of a plant canopy of finite height is solved by application of Siewert’s FN numerical algorithm. A one-dimensional, one-angle transport model is assumed with the Lambertian scattering leaves all oriented in the same direction. In addition, a Lambertian reflecting soil is assumed at the lower canopy boundary. Since the focus of this work is on the development of the FN algorithm, emphasis is given to the derivation of the algorithm and the algorithmic accuracy; however, a comparison with afield experiment is also presented to indicate the potential usefulness of the FN solution.