French art movement of the late 19th century that, inspired by scientific knowledges about the physical compositions of colours, tried to render them in an exact as possible way. To this purpose the impressionists went into nature (plein-air-painting), to catch their subjects as they were. The surrounding light conditions let contours blur and the visual impression prevails (Atomization of the objective world).
The flower piece is a special form of the still life renouncing the artificial arrangement of dead things on an image scene (table, bowl etc) and providing thus a stronger impression of reality. The flower piece has been known since the 16th century.