PSC 2620: Woody Trees and ShrubCourse HomeWeek 5

Sophora japonica - Japanese Pagodatree or Scholartree

Plant Viewer
The 6-10 inch long leaves of the Pagodatree are pinnately compound. Panicles of white flowers are shaped like pea flowers and bloom in mid-summer. Image: Wikipedia
The pea-pod are tightly wrapped around the seeds. Image: Wikipedia

Plant Description

Saphora japonica is a large shade tree that reaches 40 to 50 feet tall with a similar spread. It has a spreading form with an open and upright branching habit. It tends to be a faster grower, but I have not seen as much snow and wind breakage on specimens in the valley as I have seen with other quick-growing trees. It will withstand cold, heat and drought conditions once established, but can be difficult to get established.

The bark on young growth is an drab green color with very noticeable light grey lenticels. Mature bark is light brown and has weaving vertical ridges. The leaves are pinnately compund, 6-10 inches long, and composed of 7 to 17 leaflets. Each glossy leaflet is 1-2 inches long and ovate in shape. The canopy of the tree casts an airy shade similar to that of Gleditsia triacanthos var. inermis.

Panicles of small, cream colored flowers appear in mid-summer. The flowers are mildly aromatic, but even typically are too far from the ground to be of much appreciation. Following the flowers a 3-8 inch long pear pod forms on the tree and ripens in the fall. The pods appear to be vacuum packed around each individual seed, creating an interesting effect of a string of pearls - though I have heard it described in other, less flattering ways.

Landscape Use

Japanese Pagodatree is underused in the landscape and deserves more attention for use as a shade tree or street tree, especially since it has a high tolerance for urban pollution.