A member of the Mint Family, nettleleaf horsemint (Agastache urticifolia) is found below 9,000 feet west of the Rocky Mountains and in British Columbia. It occupies a variety of habitats but is mostly found on open slopes in montane coniferous forests.
The square stems of nettleleaf horsemint occur in masses and are 3 to 6 feet in height. The numerous opposite leaves are widely spaced along the stem. The leaves are petioled (stalked), triangular and coarsely serrate. When crushed the leaves emit a strong, minty odor.
The terminal nettleleaf horsemint inflorescence is a brushlike cluster (spike) of two-lipped flowers crowded in dense circles. The calyx is greenish or rose while the flower can range from white to pink or lavender in color. The flower lobes are bent back from the opening from which four stamens protrude. Two of the stamens are longer than the other two. The style is two-lobed.
Nettleleaf horsemint fruits are ovoid, light brown, fuzzy nutlets.
Native bees pollinate nettleleaf horsemint. Butterflies also help with pollination and drink the flower nectar.
The dried leaves and seeds of nettleleaf horsemint can be made into tea while green leaves can be used to add flavor to salads.
Nettleleaf horsemint leaves are analgesic and anti-rheumatic and were used to treat stomach pains, colds, rheumatism and measles. A poultice of nettleleaf horsemint can be used to relieve swelling.
The genus name, Agastache, derives from Greek and refers to the structure of the inflorescence: “agan” meaning much and “stachys” meaning ear of grain. The Latin for nettle is “urtica” so the species designation means “nettle-like foliage”. Another common name for A urticifolia is nettleleaf giant hyssop.
These nettleleaf horsemint specimens were growing along Lassen County California Road 510 east of California Highway 395 and Madeline.