We examined whether the AuNR orientation within the STEM scanning area led to anisotropy in the spatially dependent hot electron generation rates. The maps shown in Figure indicate that the electron beam incidence position strongly influences the hotspot spatial locations, excited resonance magnitudes, and hot electron generation rates. For instance, the transverse resonance (~520 nm) consistently exhibits intense nodes that shift in latitude with the probe position, whereas the ~620 nm higher-order mode primarily resonates only when the beam is near the nanorod center (Figure ). The position of the STEM probe with respect to the AuNR axes of symmetry mediates phase matching between the electron beam and the LSPR modes. Previous studies using electron energy loss spectroscopy (EELS) showed that placing a STEM probe near the tip or side of a AuNR preferentially excited the longitudinal or transverse LSPR, analogous to the effect of applying polarized optical light. As such, the orientation between the AuNR symmetry axes and the horizontal rastering direction of the STEM beam was hypothesized to impact the hot electron generation and silver deposition rates during LP-TEM experiments. All AuNRs displayed a monotonic decrease in particle aspect ratio (e.g., as plotted in Figure ) during LP-TEM imaging of Ag deposition, which indicated more rapid growth in the transverse direction compared to the longitudinal direction. Interestingly, we observed that the aspect ratio decreased more rapidly with increasing angle between the AuNR longitudinal axis and the direction of the STEM electron beam raster (Figure and inset). This indicates that AuNRs oriented with their transverse axis more parallel to the STEM beam scan direction experienced more rapid transversal growth.