Floating aquatic vegetation, particularly water hyacinth (Eichhornia crassipes), significantly alters open channel hydraulics by introducing surface and subsurface flow resistance to the flow. This study experimentally investigates the influence of floating vegetation on the vertical distribution of streamwise velocity and flow resistance in an open channel flume using natural water hyacinth under varied conditions of vegetation densities and root depths. Vertical profiles of streamwise velocity were measured using a Pitot tube at multiple depths, and water surface elevations were recorded to evaluate flow resistance with. The results reveal that floating vegetation alters vertical velocity profiles, forming an asymmetric velocity profile similar to that observed under ice covers or closed conduit flows. Vegetation density primarily controls surface blockage, while root depth governs vertical momentum redistribution, turbulence generation, and shear layer formation. Increasing vegetation density or root depth enhances flow resistance and intensifies turbulence near the upper flow region. These findings provide quantitative insights into the layered flow structure induced by floating vegetation, improving the understanding of energy dissipation, turbulence modulation, and resistance mechanisms. The results have practical implications for hydraulic modeling, vegetation management, and mitigation of flow obstruction in vegetated waterways.