Trichostema rubisepalum is a species of flowering plant in the mint family known by the common name Hernandez's bluecurls. The plant is endemic to California. It has a disjunct distribution occurring in two main locations: the southern Diablo Range east of the Salinas Valley in San Benito County, and the western Sierra Nevada foothills, primarily within Mariposa County and Tuolumne County. Its habitats include chaparral, foothill oak woodland, mixed evergreen forest, intermittent streambeds, and seasonal pools. It has an affinity to serpentine soils. Trichostema rubisepalum is annual herb that grows to approximately 0. 5 metres (1. 6 ft) in maximum height. Its aromatic foliage is coated in long and short glandular and nonglandular hairs. The leaves are lance-shaped. The inflorescence is a long cyme of flowers growing from the stem between each leaf pair. Each flower has a hairy calyx of pointed sepals which often take on a dark red coloration. The flower has a tubular throat and a lipped, purple corolla. The four protruding, curved stamens are about half a centimeter long. Its bloom period is from June to July.