Allium munzii is a rare species of wild onion known by the common name Munz's onion. It is endemic to western Riverside County, California, where it grows in the coastal sage scrub of the local hills and mountains at elevations of 400-900 m. It is known from only about fifteen occurrences and it is threatened by development of its habitat for human uses such as citrus agriculture and urbanization. It is a federally listed endangered species. Allium munzii is an onion that grows from a reddish brown bulb just over a centimeter long. It produces an erect stem up to about 35 centimeters in maximum height and a single leaf which is usually a bit longer. The umbel contains up to 35 flowers each under a centimeter long. They have tepals that are white with a dark green midvein, turning red with age. Pollen and anthers are yellow.