STEWARD, A. M., S. E. CLEMANTS, AND G. MOORE (Brooklyn Botanic Garden, 1000 Washington Avenue, Brooklyn, NY 11225-1099). The concurrent decline of the native Celastrus scandens and spread of the nonnative Celastrus orbiculatus in the New York City Metropolitan area. J. Torrey Bot. Soc. 130: 142-145. 2003.Before 1950, native Celastrus scandens (American bittersweet) was rather common in the New York Metropolitan area. Celastrus orbiculatus (Oriental bittersweet) was introduced into the region in the late 1800s. Analyses of the distribution of both species since the time of the introduction of C. scandens into the flora indicate that the native C. scandens has declined considerably, while the non-native C. orbiculatus has significantly spread and increased in abundance. Possible reasons for the concomitant decline of C. scandens and spread of C. orbiculatus are discussed. In the New York Metropolitan area, Celastrus orbiculatus Thunb. (Oriental bittersweet) is a commonly occurring weed, whereas the native Celastrus scandens L. (American bittersweet) occurs occasionally. Prior to introduction of C. orbiculatus, C. scandens was widespread in the area. We documented the changing distribution of both species in the New York Metropolitan area from the early 1800's through the present. We suggest several factors that may have contributed to the decline of C. scandens and the