Yerba buena is a name of Spanish origin used for a number of aromatic plants, most of which belong to the mint family. The Spanish name "yerba buena" translates as "good herb". In the Western United States, yerba buena most often refers to the species Micromeria douglasii (which is sometimes classified as Clinopodium douglasii or Satureja douglasii).
In general, in most Spanish speaking countries, the term "yerba buena" refers to the particular local species of mint, which varies from region to region. The term has been (and is currently) used to cover a number of aromatic true mints and mint relatives of the genera Satureja or Micromeria. All plants so named have medicinal properties, and some have culinary value as teas or seasonings, as well.
The specific plant species regarded as "yerba buena" varies from region to region, depending on what grows wild in the surrounding landscape, or which species is customarily grown in local gardens. Perhaps the most common variation of this plant is spearmint (Mentha spicata).
In parts of Central America yerba buena often refers to Mentha citrata, a true mint sometimes called "bergamot mint" with a strong citrus-like aroma that is used medicinally and as a cooking herb and tea. In Cuba, yerba buena generally refers to Mentha nemorosa, a popular plant also known as large apple mint, foxtail mint, hairy mint, woolly mint or, simply, Cuban mint. In Puerto Rico a close relative of traditional culinary savory, Satureja viminea, is sometimes used. In Peru the name is sometimes applied to a shrubby aromatic marigold, Tagetes minuta also known as huacatay or "black mint"; in this case, despite some similarities of flavor, the herb in question is in the Sunflower family and is quite unrelated to any of the mints or mint-relatives with which it shares a name.