Elsholtzia ciliata

Elsholtzia ciliata is a weed native to Asia, sometimes grown as an ornamental plant.

The plant is an erect herb that grows to about 60 cm in height. The leaves are long, stalked, and serrated, and reach 2 to 8.5 cm in length and .8 to 2.5 cm in width. In shape they are ovate to lanceolate, with a gland-dotted underside. Flowers of a purple color bloom in flat spikes in September and October. Seeds propagate within them.

The plant is native to Asia; however, the exact extent of its original range is unclear. Today it is found throughout Nepal at elevations of 1500 to 3400 m. It is found elsewhere, including through much of India, eastern Asia, and Europe. In modern times it has become popular as an ornamental plant, though first being reported in the Americas as a weed in 1889. It prefers moist soil, and grows mostly on exposed rocky slopes and other open, gravelly areas.

Elsholtzia ciliata has many cultural uses. The seeds are sometimes powdered and used for flavoring food. Additionally it is common in traditional medicine, as it is carminative and astringent.

It is used in Vietnamese cuisine, where it is called rau kinh giới.