Turbines and associated components, systems, and methods are described. In some embodiments, the turbine blades and turbines are configured to convert kinetic energy present in fluid (e.g., water) to other forms of energy (e.g., in a hydrokinetic energy system in a river or ocean) relatively efficiently and/or at relatively low cut-in speeds. The turbine blades may have a shape and/or include structural features that contribute at least in part to relatively high efficiency and/or relatively low cut-in speeds. In some embodiments, the turbine blades have a geometry similar to the geometry of a maple seed.