Monardella antonina is an uncommon species of flowering plant in the mint family known by the common name San Antonio Hills monardella. It is endemic to California, where its two subspecies are restricted to narrow sections of the Central Coast Ranges. The distribution of ssp. antonina is unclear, but it is mainly found in chaparral and wooded slopes in Monterey County. The rarer ssp. benitensis, the San Benito monardella, is a serpentine soils endemic which is mainly limited to the barren hills near the ghost town of New Idria in San Benito County. This is a pale green, rhizomatous, hairy perennial herb coated in whitish hairs. The oppositely arranged leaves are oval in shape and generally toothed. The flower cluster is a head of several flowers up to 1.5 centimeters wide with a base of leaflike leafs. Each flower is lavender in color. It has two long upper lobes and three lower with four long, protruding stamens at the center.