Because biodiversity is debated primarily from western perspectives, the significance of threatened taxa has not been properly assessed in the cultural and ecological contexts of their use. Instead, conservable species tend to be identified by outsiders who are culturally and politically detached from the threatened environments. However, over the last decade or so a growing number of studies document why and how indigenous knowledge and people can become part of development and sustainable conservation. Presented here is a Nigerian example that illustrates how formal conservation efforts are handicapped by their failure to take into account local environmental knowledge. I argue that the potential erosion of biodiversity in Hausaland has been checked by the varied management of cultivated and other lands, and by the use of plants in overlapping contexts—as medicines, foods, and the like.