(n.) One skilled in botany; one versed in the knowledge of plants.

anatomist bacteriologist biochemist biologist biometrist biophysicist bryologist cytologist dendrologist ecologist geneticist herbalist mycologist natural scientist naturalist physiologist phytobiologist phytoecologist phytogeographer phytographer phytologist phytonomist phytopaleontologist phytopathologist phytoteratologist pomologist zoologist