Red Flower

What is the purpose of stylized red flower worn by british men on their jacket’s buttonhole?What flower is?

I saw often in movies or on tv british men with tuxedos or other costumes wearing a stylized red flower on their jacket’s buttonholes and I was wondering what is the purpose of that flower. Can anyone answer me, please?

Its probably a poppy in remembrance of those who died in wars.

flowers are red Zain Bhikha