WASHINGTON – Black women and their hair have been a topic of discussion for years by people like Maya Angelou, Al Sharpton and Salt-N-Pepa.

Now add Defense Secretary Chuck Hagel to that list.

In reaction to a new Army regulation banning numerous hairstyles — twists, dreadlocks and large cornrows — popular with black women, the 16 women of the Congressional Black Caucus have asked Hagel to overturn the regulation on behalf of the 26,700 African-American women on active duty in the Army. The regulation comes at the same time as a new Army rule banning tattoos on the face, neck, hands, fingers and lower arms of recruits.

Both regulations are among new grooming standards critics say are meant to further weed people out of an Army reducing its size from its post-9/11 peak of 570,000 to as low as 420,000 in the years to come. Rep. Marcia L. Fudge, D-Ohio, chairwoman of the black caucus, said she had been struck in recent visits to military bases by how many soldiers said they felt they were being pushed out of the military. The new regulations, announced March 31, have intensified that feeling, she said.

Although the new rules on tattoos have come under fire, the regulations on black hairstyles have drawn more outrage and charges of racism. By Friday, more than 17,000 people had signed an online petition sent to the White House to get the hair regulations rescinded.

At the root of the concern about the Army regulations, many black women said, is a lack of understanding about black hair. While black hair comes in all textures, much of it is deeply curly, making it difficult to pull back into a bun or to hang loose off the face in a neat, uniform way.

Defense Department officials said Hagel “appreciates the Congressional Black Caucus’ concerns regarding this issue,” said Lt. Cmdr. Nathan Christensen, a Pentagon spokesman. But, he added, “We expect the Army to provide a response shortly.”