Styphnolobium japonicum is a deciduous ornamental tree from China, grown for its late-summer white flowers and dense shade. It is a tree rather than a houseplant, so the care notes below apply to a planted tree outdoors.
Family
Fabaceae (Pea & bean family)
Grows as
Tree
Light
Full sun, Part shade
Water
Water deeply during dry spells while young; established trees are fairly drought tolerant.
Soil
Well-drained soil, tolerant of many soil types and mildly alkaline conditions.
Temperature
Hardy to about -20 °C; tolerates hot summers.
How easy
Easy
Safety
Mildly toxic: Seeds, bark and fruit contain alkaloids such as cytisine and matrine; eating parts of the plant may cause nausea or other discomfort.
Native range
C. & S. China
Climate
temperate
About
Styphnolobium japonicum, the Japanese pagoda tree (also known as the Chinese scholar tree and pagoda tree; syn. Sophora japonica) is a species of deciduous tree in the subfamily Faboideae of the pea family Fabaceae.
It was formerly included within a broader interpretation of the genus Sophora. The species of Styphnolobium differ from Sophora in lacking the ability to form symbioses with rhizobia (nitrogen fixing bacteria) on their roots. It also differs from the related genus Calia (mescalbeans) in having deciduous leaves and flowers in axillary, not terminal, racemes. The leaves are alternate, pinnate, with nine to 21 leaflets, and the flowers in pendulous racemes similar to those of the black locust.
Safety
The dried flower buds may contain as much as 20% rutin with some quercetin. S. japonicum dried fruit contains the flavonoid glycosides sophoricoside, genistin and rutin and the flavonoid aglycones genistein, quercetin and kaempferol. Another analysis found genistein and genistein glycosides including sophorabioside, sophoricoside, genistein-7-diglucoside, genistein-7-diglucorhamnoside, and kaempferol and the kaempferol glycosides kaempferol-3-sophoroside and kaempferol-3-rhamnodiglucoside. The fruit also contain the alkaloids cytisine, N-methylcytisine, sophocarpine, matrine and stizolamine. The bark contains the allomatrine alkaloid.
Where it grows
Styphnolobium japonicum is native to China. Despite its Latin name, the species was introduced in Japan and not originally found there. It is a popular ornamental tree in Europe, North America and South Africa, grown for its white flowers, borne in late summer after most other flowering trees have long finished flowering. It grows to 10–20 m tall with an equal spread, and produces a fine, dark brown timber.
Text excerpted from the Wikipedia article Styphnolobium japonicum by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.