This paper examines the process and outcome of participatory methods for stakeholder identification. We used focus group style participatory methodology to engage local residents in identifying key sub-groups relevant to conservation in Boumba, Niger. We then conducted a quantitative pictorial recognition study to measure the diversity of local useful plant knowledge across groups. The community identified six gender and age-class groupings relevant to the study. The effect of a participant's gender, socially-defined age class or the interaction of the two factors on the number of plants recognized varied by plant use. Medicinal plant knowledge was highest among elders. Food plant knowledge of food plants increased with age for women only. Where as the interaction of age and gender was strongest on fodder plant knowledge, where mid-aged men scored highest. We reflect on the impact that heterogeneity of local botanical knowledge has on our understanding of local natural resource use and the strengths of using a participatory approach to identifying the stakeholder groups which underlie this heterogeneity.