Friday, August 9, 2013

Sophora japonica - Japanese Pagoda Tree

A Japanese Pagoda tree is a rare site around here, I have seen only a few. Looking like almost all the other deciduous trees with pinnately compound leaves, it has a few distinct characteristics.  Growing quite large, the one on Sumner Dr. is very typical, reaching 50' with a broad wide spreading crown.



Usually do not develop fall color, but heck, this one did.



Leaves are deciduous, alternately arranged, pinnately compound to about 10" with 7 to 15 or so leaflets. Leaflets are medium to light green, narrowly ovate to lanceolate, 1-2" long.  



Typical of may plants in the pea family it has swollen petiole bases.



Also a bit different is the flattened petiolule (leaflet petiole) of the leaflet. You can also see some whitish hairs on the veins.



Stems are green, for a long time. Hidden under the swollen petiole base is a black bud. Not many plants have black buds.



Flowers are small pea-like, yellowish white appearing late July. Lasting only a few weeks they soon fall and cover the ground. Borne in large 12" long by 12" wide clusters.






Fruit is a bean like pod, but with distinct constrictions between each "pea" inside. Persistent through winter. Interesting but can be messy.



Native to China and Korea but not Japan .... who makes up these common names anyway, and I guess its new botanical name is Styphnolobium japonicum


Misidentification:
wow, how many plants do we have that look like this? Robinia, Tipuana, Gleditsia, Cassia, the list goes on.

Green stems, often for several years. Black bud. Fruit with constrictions between the seeds.

Location
Aptos
448 Sumner Dr.

Santa Cruz
Harvey West Park, behind the children's play area are 2 fairly young trees.