Tridax procumbens, commonly known as coatbuttons or tridax daisy, is a species of flowering plant in the family Asteraceae. It is best known as a widespread weed and pest plant. It is native to the tropical Americas including Mexico, but it has been introduced to tropical, subtropical, and mild temperate regions worldwide. It is listed as a noxious weed in the United States and has pest status in nine states.

Its common names include coatbuttons and tridax daisy in English.

Names in other European languages include cadillo chisaca in Spanish and herbe caille in French.

Among Indo-Aryan languages, it is known in Sanskrit as jayanti veda (जयंती वेद) or avanti. In Gujarati it is called ghajadvu or ghaburi (ઘાબુરી). In Assamese it is known as bikhalyakarani. In Hindi it is known as ghamra, and in Urdu it is called zagh mai hayat. In Bengali it is called tridhara (ত্রিধারা). In Marathi it is called kambarmodi, jakhamjudi or tantani (कंबरमोडी, जखमजुडी and टनटनी, respectively).

Among Dravidian languages, it is called jayanthi (ಜಯoತಿ) in Kannada, while it is known in Malayalam by the names kumminnippacha (കുമ്മിനിന്നിപാച്ച), kurikootticheera (കുറികോട്ടിച്ചിചിറ), muriyampachila (മുരിയമ്പാചില), odiyancheera (ഒഡിയൻ‌ചിറ), railpoochedi (റൈലാപൂച്ചെഡി), sanipoovu (ഷാനിപോവ്), thelkuthi (തെക്കുത്തി) or chiravanakku (ചിരവനാക്ക്).

In Oriya, it is called bishalya karani (ବିଶଲ୍ୟକରଣୀ). In Telugu, it is called gayapaaku (గాయపాకు), gaddi chemanthi (గడ్డి చామంతి), or balapaaku (బలపాకు). In Tamil it is called vettukaaya poondu, thatha poo or kinatruppasan (கிணற்றுப்பாசான்) and it is called kurunagala daisy in Sinhala.

It is called kotobukigiku in Japanese and tīn túkkæ (ตีนตุ๊กแก; 'gecko feet') in Thai.

The plant bears daisy-like yellow-centered white or yellow flowers with three-toothed ray florets. The leaves are toothed and generally arrowhead-shaped. Calyx is represented by scales or reduced to pappus.