Segetal plants, or “messicoles” as they are known in French, are weedy inhabitants of wheat crops (mainly winter cereals). The national list of segetal species includes 102 taxa; of which 7 are extinct, 52 threatened, 30 to be kept under close observation and 12 abundant. Data on their distribution indicates that they are mostly in decline due to intensive farming systems. As their survival is intrinsically linked to farming systems, we need to improve knowledge on their relationships with land management in order to establish a sound scientific basis for protection tools, to support and guide farmer conservation measures and to disseminate concerns for segetal biodiversity to agro-environmental policymakers. We propose to examine: 1) the relationships between the abundance and/or the segetal richness (flora sampling) and farmer practices (farm evaluation conducted using the “Dialecte” software) in several farms in different regions, especially in segetal-rich areas; 2) the potential ecosystem service provision as resources for foraging insects through identification of the pollen of segetal plants and their abundance in pollen traps fixed on bee hives; 3) the perception of segetals (e.g. as troublesome weeds, or anecdotal biodiversity, or beautiful floral component of the landscape, or plant for services, etc) by professional actors (farmers, technical advisers, actors of biodiversity preservation initiatives, regional collectivity and regulatory authorities, etc) to identify ways of thinking that underlay the diversity of discourses and present practices about them. Joining national efforts for similar goal and participatory approach could help European Community to adopt agro-environmental measures towards biodiversity conservation without cutting productivity.