Porophyllum ruderale (commonly known as papalo, quirquiña/quilquiña, or yerba porosa) is an annual aromatic herb in the daisy family (Asteraceae). The genus name Porophyllum derives from Greek poros (“pore”) and phyllon (“leaf”), referring to the visible glandular pores on the leaves that release essential oils. The species epithet ruderale comes from Latin ruderalis (“growing among waste or disturbed ground”), describing its weedy, hardy growth habit. It is native to Mexico, Central America, and parts of South America, and has long been cultivated and foraged as a culinary and medicinal plant. The plant is characterized by its broad, oval leaves dotted with glandular oil-containing pores that release a strong aroma when crushed.

Historically, P. ruderale was used in pre-Columbian Mesoamerican cuisine as a seasoning herb, valued for its pungent, cilantro-like flavor but with notes of arugula and citrus. In modern times, it remains an important traditional herb in Mexican, Bolivian, and Peruvian cuisines, where it is eaten fresh in tacos, salsas, and sandwiches (such as the Mexican cemita poblana), or used in soups and stews. Medicinally, it has been used as a digestive aid, antimicrobial, and in folk remedies for high blood pressure.