Staphylea japonica aka Staphylea Japonica

Staphylea japonica is known as the Korean sweetheart tree. Older sources call it Euscaphis japonica. It belongs to the bladdernut family, Staphyleaceae. Its native range includes China, Korea, Japan, and northern Vietnam. It grows in valleys, thickets, and open woods. This deciduous plant forms a large shrub or small tree. It remains scarce in cultivation.

Garden plants reach 12–20 feet [3.7–6.1 metres] tall. Some reach 30 feet [9.1 metres] over time. Sources give widths of 8–15 feet [2.4–4.6 metres]. Growth proceeds at a moderate rate. Open, uneven branches give the crown a spreading shape. The bark has purple and brown tones with white stripes. These marks stand out when the branches lose their leaves. The leaves grow in opposite pairs and have a pinnate form. Each leaf holds seven to eleven glossy green leaflets. These feel leathery and have fine teeth and pointed tips. Fall brings deep brown, copper, and purple leaf tones.

Small yellow to yellow-white flowers open in May and June. They grow in panicles at the ends of branches. The blooms draw less attention than the fruit that follows. The plant bears many seed capsules with a heart-like shape. These turn bright red in fall, then split open. The open capsules reveal black seeds within. The fruit and fall leaves provide late-season garden interest. The striped bark adds interest through winter. Gardeners can use the plant as a specimen near woodland edges.

Grow it in full sun or part shade. Sandy soil or loam suits it when drainage is good. It grows best with a steady supply of soil moisture. It can endure short dry spells despite this preference. Avoid sites with hot, dry summers. Sources place its cold hardiness in USDA zones 6–8. Care needs are low, and no serious pest problems are reported. Sources also report no serious disease problems. Transplants offer better prospects than attempts to raise plants from seed.

Plants For A Future lists leaves and young buds as food. It gives their edible value a low rating. Details on preparation are absent from the supplied evidence. That source also records a medicinal use for the fruit. It gives no details about its purpose or preparation. Its hazard entry reports none known. This does not establish that every plant part is safe to eat.