Montanoa is a genus of attractive, woody Asteraceae, appropriately referred to as the "Daisy Trees" because of their white rays and yellow disc florets. Most members of this genus are shrubs, but a few are truly arborescent, and when in flower they present a spectular display. The genus is widespread in Latin America and several species are cultivated in the warmer parts of the world. This treatment of Montanoa recognizes twenty-two species, in two subgenera, from the over 100 previously described. There are three new species described here. Data collected from extensive field and herbarium studies were combined with the results of greenhouse experiments to deterimine the usefulness of characters for species determination. Includes keys; descriptions; distribution, habitat, and phenology information; and black and white illustrations.