A Native American student took a California school district to court on Monday after his high school banned him from wearing an eagle feather on his graduation cap, a civil rights group said.

The American Civil Liberties Union of Northern California (ACLU) said Clovis High School senior Christian Titman, 18, had notified the court of the emergency lawsuit ahead of his Thursday graduation.

Titman, a member of the Pit River Tribe, and his parents have repeatedly asked that he be granted permission to wear the feather during the ceremony to represent his heritage and religion, and mark his academic achievement, but their requests were denied, according to the ACLU.

"The eagle feather is not only a signature of my tribe but it also represents the pride I have for my tribe, my people and my heritage," Titman told the local Fresno Bee newspaper on Monday. "When I have feathers on I'm connected with ancestors before me."

Clovis School District spokeswoman Kelly Avants said in an email that it has long banned non-academic accessories from being worn during the ceremony to maintain uniformity across the graduating class.

Avants said the district offered to allow Titman to receive the feather as he gets his diploma or let him wear it during portions of the ceremony, but the offers were rejected.

"The District remains committed to attempting to reach a resolution that respects both Christian's Native American culture and traditions, and the long-standing traditions surrounding our content neutral graduation ceremony standards," Avants said.

The ACLU said the California Constitution and state Education Code provide protection for religious expression and student free speech.

"The district's refusal to allow a small symbol of religious expression during the graduation ceremony is a misunderstanding of both the spirit and the letter of the law," ACLU staff attorney Novella Coleman said.