Scientific Name
Styphnolobium japonicum
This tree is named because it was often planted near Buddhist temples in east Asia. It is also sometimes called Chinese Scholar tree, which is appropriate because it is native to that country and not to Japan, where it was later introduced. It was formerly assigned to the more melodious-sounding genus Sophora but was renamed because of the lack in ability to fix nitrogen in the soil in association with bacteria living in its roots. It typically grows to a mature height of around 55 feet here; the current Colorado champion is in Denver and is 82 feet tall. The leaves, alternating on the branches, are compound with small leaflets. The bases of the leaf midribs are large and totally conceal the buds. A good clue to its identity is its prolific production of white flowers later than the bloom of most other trees, in late July or August. Other clues are the twigs, which are smooth and an unusually dark yet bright green, and the fruit, a pod (yes, another pea family plant) with a row of seeds inside. As the seedpods mature, their outer shells shrink around the seeds, giving the pods a kind of “string of beads” look. The bark retains its green color for quite a few years and takes some time to develop toughness, which can make it vulnerable to mechanical damage when young.
Pagoda tree has proven to be a useful tree in cold-climate urban areas and is adaptable to poor soil, drought and heat. Various parts of the plant contain an interesting array of chemicals and have been used for millennia as one of the 50 fundamental herbs of traditional Chinese medicine.