Yerba santa (Eriodictyon glutinosum and Eriodictyon californicum) is a short evergreen shrub that grows in dry, hilly areas of California and Northern Mexico. The plant, part of the Hydrophyllaceae family, grows in clusters and is approximately 3 ft (1 m) in height.
The smooth stem and thick yellow leaves are covered with a resin, and the plant has blue flowers that cluster together in groups of six to 10. The leaves are 2–5 in (5–12 cm) long.
The plant contains chrysocriol, eridonel, eriodictyol, formic acid, glucose, glycerides of fatty acids, homoeriodictyol, resin, tannic acids, tannins, volatile oil, and zanthoeridol. The leaves should be gathered in the spring and early summer.