In 1959, the Legislature designated the native species, Rhododendron macrophyllum, as the official flower of the state of Washington. The State Flag The state flag and the state seal are similar. Passed in 1923, Washington law describes the flag as having dark green bunting with a state seal in the center. In the late 1890s, a blue and gold military state flag with George Washington's profile on it flew over many cities and towns throughout the state. But when it came to a final decision, the current flag was adopted by the Legislature.