Forsythia suspensa is one of the 50 major herbs used in Traditional Chinese Medicine. This photo was taken in the Zoological & Botanical Garden, Hong Kong.
2011-10-09 Vienna XXII. district - Danube National Park (Lobau Hausgraben - bayou 153 msm Quadrant 7865/1).See also remarks here.What you can see here of course is mainly Fraxinus excelsior (bent by the wind, bearing fruit), but there's also Salix and Populus (and others) present here.