Aloysia scorodonioides

Native to western South America, northern Brazil, and northwestern Argentina, this aromatic shrub can reach about 13 feet tall. It grows in seasonally dry habitats, including river margins and dry woodland in Argentina. Its small white, pink, or purple flowers form spikes that arise singly from the leaf axils. The leaves have a strongly wrinkled surface and often a pale, hairy underside. Considerable variation in leaf shape and flower-spike density occurs across its range. Photographed in Peru.