Acceptance of the plant group Martyniaceae, which contains the genus Proboscidea (commonly known as devil's claws or unicorn plants), as a distinct family has long been questioned. Previously placed in the family Pedaliaceae, commonly known as the Sesame family, the Martyniaceae have been allied to numerous other families within the order Lamiales. For this study, sequences of chloroplast DNA from the ndhF and rps16 regions were used (1) to demonstrate the monophyly of the Martyniaceae and (2) to identify the closest living relative to the group. Preliminary data suggest that the Martyniaceae are distinct from the Pedaliaceae, and that the Verbenaceae, commonly known as the Verbena or Vervain family, may be the closest living relative to the family Martyniaceae. If the Martyniaceae and Verbenaceae are sister groups and most closely related to each other, then there are interesting biogeographic implications that can be suggested from the results. The Verbenaceae are primarily from arid areas of South America, which happens to be one of the centers of diversity for the family Martyniaceae. If the Verbenaceae are the most closely related group of plants to the family Martyniaceae, then it can be suggested that the Martyniaceae may have had an origin in South America, then dispersed into and diversified in North America.