Plant science Botany 9 Plant physiology 4 Chromosome 3 Ethnobotany 3 Morphology 3 Paleo Botany 3 cell structure 3 Genetics 2 Histology 2 Nitrogen fixation 2 hydraulic conductivity 2 plant organisms 2 plant physiology 2 stem modification 2 Algae 1 Bacteria 1 Cell 1 Cell chemistry 1 Cell growth 1 Germination 1 Nitrogen cycle 1 Oceannography 1 Paleobotany 1 Photosynthesis 1 Plant pathology 1 Plant poisons 1 Plant taxonomy 1 Plant tissue culture 1 Seed germination 1