Poo-Robinietum is an association of open and mesic Robinia woodlands with the herb layer dominated by grasses, particularly Poa nemoralis. Nutrient-demanding dicot herbs are less common than in the Chelidonio majoris-Robinietum pseudoacaciae. It is usually found on slowly weathering siliceous bedrocks on upper and middle slopes in deep river valleys of the Bohemian Massif. Localities in the Czech Republic are concentrated in the river valleys of central and southern Bohemia and south-western Moravia.