M. Thulin (2006) Verbenaceae. Flora of Somalila 3: 356-366
Plants Shrubs, subshrubs, or perennial herbs; synoecious or dioecious. Leaves opposite or in whorls of 3-4, entire, toothed, or lobed. Inflorescences dense heads or spikes, each flower subtended by a bract. Flowers slightly bilaterally symmetric; calyces undulate, truncate, or lobed; corolla tubes cylindric or funnel-shaped, straight or curved; limbs somewhat 2-lipped; stamens 4, included or slightly exserted; ovaries 2-celled, each cell with 1 ovule; stigmas oblique.Fruits dry, surrounded by the appressed calyx, separating into 2 nutlets at maturity.
Lippia includes about 200 species, most of them being native to Central and South America.