Solar-excited plant fluorescence in the red/near-infrared is known to fill Fraunhofer lines at ground level. In this paper, it is shown that red/near-infrared fluorescence by vegetation can fill Fraunhofer lines much more effectively than rotational Raman scattering (RRS) by air (Ring effect) for nadir viewing from satellite altitudes. Thus, similarly to RRS, plant fluorescence can be remotely sensed from an orbiting spectrometer, and may impact the retrieval of atmospheric trace gases such as water vapor by high-resolution spectroscopy over vegetated land.