Thorneochloa is a genus of flowering plants belonging to the family Poaceae.

It contains a single species, Thorneochloa diegoensis,[2] commonly known as San Diego needlegrass.

[4] Thornelochloa diegoensis is a bunching perennial grass reaching heights between 110 and 140 centimeters.

[3] Thornelochloa diegoensis is native to southern California, where it is known from San Diego and Ventura Counties and the Channel Islands, and Baja California.

[3] It is a resident of chaparral and coastal sage scrub ecosystems below 350 feet in elevation, especially near streams.