Urbanisation is known to change biodiversity patterns and plant-animal interactions such as pollination - a key ecological process. Floral traits like colour, size or UV-patterns are essential attractors for many pollinators. It is largely unknown, though, how the distribution of such floral traits within plant communities changes along an urbanisation gradient. This study aims to understand to which extent floral traits known to attract pollinators are filtered by urban environments. We used dry grassland, spanning a broad urbanisation gradient in the Berlin metropolitan area, Germany, as a model ecosystem and identified the distribution of plant traits related to bee-perceived flower colours, UV reflection and flower size in 47 grassland patches. We analysed how these traits were related to abiotic and biotic factors at different spatial scales. The most influent predictor was an abiotic factor measured at the landscape scale: the proportion of impervious surface, found to be positively related to UV-reflectance strength and floral UV patterns, but negatively to floral size diversity. At the local scale, abiotic factors showed an intermediary number of relationships. Temperature was negatively associated with the bee-colour 'green + UV-green' and with flower size. The light environment was negatively related to the same bee-colour and to floral size diversity. Biotic factors related to local pollinator communities were less important: species richness was negatively related to flower size, while proportion of bees to floral sizes diversity. This study shows that floral traits known to attract pollinators are mostly filtered by abiotic factors related to urbanisation (share of impervious surface) or the urban heat island (local temperature). Biotic factors related to local pollinator communities were less important. These results increase our functional understanding of plant-animal interactions in cities by illustrating how urban environments modulate the attractiveness of plant communities to pollinators by filtering for floral plant traits.