about 40, see text Aloysia is a genus of flowering plants in the verbena family, Verbenaceae.

[3] The genus is named for Maria Luisa of Parma (1751-1819), wife of King Charles IV of Spain.

[4] The stems may be four-angled and smooth when new, becoming more angular or rounded and often furrowed or striated with age.

The blades are variable in shape, toothed or smooth-edged, and hairless to rough-haired on the upper surfaces.

The flower corolla is tubular with a wider mouth divided into four lobes, one of which may be cleft.