Growth form
The usually short-stemmed Koelreuteria has a broad, open, but often crooked crown. In its teens, the small tree or large shrub is rather rounded, later becoming flatter and umbrella-like, reaching a height of 6 to 8 meters. Mature specimens may be as tall as they are wide; however, the width is generally around 5 meters. This applies to older specimens; annual growth is only 10 to 20 cm. This makes the bladder tree suitable for small gardens, to a limited extent.
leaf and flower
Seven to fifteen oblong, incised leaflets comprise dark green, odd-pinnate leaves that turn a pretty yellow-orange to orange-brown in autumn. The tree's value lies in its late blooms, which appear from late July to late August, a delicate pink at first, later greenish, and bright yellow towards autumn. They appear as loose flower spikes 15 to 30 centimeters long.
Towards the end of flowering, the impressive, lantern-like fruit develops from parchment-like capsules. It remains on the tree for a long time (well into spring) and has a striking green color at first, later turning reddish-brown. In its native Japan, these capsules are used to make a rosary.
