plant stem Plant Stems 54 plant leaf 42 Plant Leaves 40 article 40 physiology 38 water 36 Water 34 metabolism 30 xylem 24 hydraulic conductivity 22 Argentina 20 Trees 18 growth, development and aging 18 nonhuman 18 plant root 18 stomatal conductance 18 tree 18 Plant Roots 16 Plant Transpiration 16 Xylem 16 evapotranspiration 16 Wood 14 chemistry 14 wood 14 Photosynthesis 12 controlled study 12 photosynthesis 12 Plant Stomata 10 cavitation 10