1. A plant species identification apparatus for identifying plant species, the apparatus comprising a processor configured to perform a process including: storing reference spectral data which indicate a reflectance spectral feature classified by area segments including a sunlit portion and a shaded portion in addition to the plant species, to a reference data storage part; acquiring hyperspectral data to be a target; specifying the reflectance spectral feature of a pixel for each of pixels of the hyperspectral data from the reference data storage part; and determining the plant species of the pixels based on a classification of the reference spectral data.