A derivation is presented for the fraction of material transformed as a function of time, X(t), for one-dimensional phase transformations which occur via continuous nucleation and growth and which produce anisotropic particles. This derivation, which accounts for shielding effects and does not assume site saturation, is the first such derivation given for this type of problem. The analytical formulas which are found are evaluated in an approximate fashion for two different values of growth rate anisotropy. The results are compared with numerical simulations, and it is shown that the expressions derived are highly accurate.