Monardella undulata subsp. undulata, synonym Monardella frutescens, is a rare subspecies of flowering plant in the mint family known by the common name San Luis Obispo monardella.[1]
Monardella undulata subsp. undulata is a perennial herb producing several purple stems. The thin, narrow, wavy-edged leaves are 1 to 5 centimeters long and borne in clusters along the stem. The inflorescence is a head of several flowers blooming in a cup of papery purplish to straw-colored bracts.[2] The flowers are rose-purple to purple in color. This subspecies may hybridize and so intergrade with its relative, Monardella undulata subsp. crispa, where their distribution overlaps.[1]
Monardella undulata subsp. undulata Habitat includes dunes and coastal areas.[3] It is endemic to California, where it is known only from the sand dunes and coastal sage and chaparral scrub on the coastline of San Luis Obispo County.[1]
Monardella undulata subsp. undulata is threatened by coastal development.[1]