The flag of Texas is the official flag of the U.S. state of Texas. It is well known for its prominent single white star which gives the flag its commonly-used name: "Lone Star Flag". This lone star, in turn, gives rise to the state's nickname: "The Lone Star State." The flag, flown at homes and businesses statewide, is highly popular among Texans and is treated with a great degree of reverence and esteem within Texas.

Answer this question: why is the texas flag called the lone star flag? Let's give stream of consciousness first:
This is the relevant information: It is well known for its prominent single white star which gives the flag its commonly-used name: "Lone Star Flag".
So, the final answer is for its prominent single white star.