Philadelphus pekinensis (mock orange, 太平花 tai ping hua) is a species of deciduous shrub, high, endemic to northern and western China and Korea, with fragrant flowers up to 1" across in small clusters.
Synonyms Philadelphus coronarius var. pekinensis Maxim. Philadelphus pekinensis f. lanceolatus S.Y. Hu Philadelphus pekinensis var. pekinensis Philadelphus rubricaulis Carrière
References
Missouri Botanical Garden entry