Hirsuties coronae glandis (also known as hirsutoid papillomas and pearly penile papules; PPP) are small protuberances that may form on the ridge of the glans of the human penis. They are a form of acral angiofibromas. They are a normal anatomical variation in humans and are sometimes described as vestigial remnants of penile spines, sensitive features found in the same location in other primates. In species in which penile spines are expressed, as well as in humans who have them, the spines are thought to contribute to sexual pleasure and quicker orgasms. It has been theorized that pearly penile papules stimulate the vagina during sexual intercourse. In addition, pearly penile papules secrete oil that moistens the glans of the penis.