The J.J. Pearce High School homecoming football game was underway on a hot, breezy Friday night. Up in the bleachers, tubas swayed from side to side as if waving hello, and bare backs rippled with red and blue paint that spelled, “Go Mustangs!”

As the team charged down the field, a strange roar was building in the stands — the chorus of hundreds of cowbells swinging to and fro on the homecoming mums.

Mums are elaborate adornments typically worn by female students in a tradition across the South and Midwest that goes back more than a century. They have become as much a part of homecoming celebrations as the football games. In Texas, they have evolved into a statement-making ritual: The larger and louder the mum, the better.

“When you walk through the halls, you hear bells,” said Sydney Brown, a senior and student government secretary at Pearce, a public high school with nearly 2,500 students located in the Dallas suburb of Richardson. “You see feathers on the ground. My friend said it looks like when you’re leaving a Harry Styles concert.”

Each year, teachers resign themselves to the noise. Students laugh as their classmates reveal their many shades of personal expression. Girls complain of being weighed down, at times with feigned annoyance. After all, a heavy mum is a status symbol. And they are heavy — many weighing up to 10 pounds. Knees may bruise if a cowbell is placed so that it knocks against bone. The neck strains.

“It gets heavier each year,” said Adalyn Hardeman, a junior involved with the golf team and photography club. “Every year, I get it a little more blinged.”

Mary Margaret Anthony, a Pearce senior and the first lieutenant on the drill team, said that, from an early age, she admired the older girls wearing mums at football games and dreamed of when it would finally be her turn.

“They’re celebratory,” she said. “Everybody has the best energy all day.”

The teddy bear at the center of Ms. Anthony’s mum was dressed in a miniature version of her blue-and-white first lieutenant’s uniform.

The basic structure goes like this: An oversized polyester or paper flower in the shape of the mandala-like chrysanthemum (hence the name) is affixed to a cardboard backing; in the center sits a small teddy bear, which is dressed in an outfit reflecting the student’s interests; bows, feather boas, ribbons and plastic accouterments cascade from the flower to the shins.

The entire concoction is then pinned to a student’s shirt or attached to a thick ribbon that hangs around the neck. Male students wear a more compact version, known as a garter, which is held to the upper arm with an elastic band.

The arrangements became more elaborate starting in the 1980s, having grown considerably since the days when a boy commemorated homecoming by giving a simple chrysanthemum corsage to a girl, and received a garter in return.

Artificial flowers became the norm when the tradition became so popular that florists couldn’t keep up with demand, said Amy J. Schultz, the author of “Mumentous,” a book published this year on the history of mums. Adding ribbons in school colors became popular after World War II, she said, when the corsage became an extension of school spirit.

The size and composition of the accessories aren’t the only things that have changed. These days, mums are not necessarily part of courtship rituals. A great number of students buy their own and go in full regalia to the football game and related events without a date. Ms. Brown, the Pearce student government secretary, was among the seniors who celebrated homecoming with a group of friends. “You don’t need a date to have a mum,” she said. “Buy yourself a mum!”

The ornamentation can be costly. Pearce students said they paid between $94 to $160 for their mums. That’s on the low end for Texas, where they may cost as much as $500.

The majority of Pearce students bought their arrangements at the Pearce Mum Store, which started in 2003 and is run by parent volunteers. It opens for business in the weeks leading up to homecoming, but some volunteers spend 10 months preparing basic skeleton mums, cutting and braiding ribbons assembly-line style. They made 765 mums this year.

“It’s a lot of hot glue,” said Shayla Cobb, a Pearce mother and the P.T.A. co-chair of the store.

There are 28 ribbons on each mum. That means more than 20,000 ribbons, including name loops, braids and whips (cylindrical, basket-like ribbon shoots), had to be cut this year. Little disco balls have trended up in recent years, and feather boas were in limited supply because of supply chain issues, Ms. Cobb said. Each bauble — a variety of plastic football helmets, megaphones and state-of-Texas decals called “trinkets” — is sold à la carte for $1 to $5. Cowbells are included.

And then there are the bears.

“Teddy bears happened during the jump from real to artificial flowers,” Ms. Schultz said, adding that they “became a way to customize your mums in a way that personifies you.”

Mehrana Hosseinpour, a senior who is part of the swim team, orchestra and student government, opted for a bear in a swimsuit with minuscule goggles. Her boyfriend added a tiny violin. Ms. Hosseinpour wrote “STU GOV” on the bear’s towel so that all three organizations were represented. Last week’s homecoming celebration marked the first time she had worn a mum, she said.

“It makes me feel like a cow, if I’m being honest,” Ms. Hosseinpour said. “But it is fun.”

As for the big game? The Pearce Mustangs beat the Nimitz High School Vikings, 50-28.