Acer cissifolium aka Japanese Box Elder

Acer cissifolium is a small tree from Japan's mountain regions. It belongs to the soapberry family, Sapindaceae. Common names include ivy-leaved maple and vine-leaved maple. The tree sheds its leaves each year and grows slowly. Garden trees reach 20–30 feet (6.1–9.1 metres) tall and wide. The RHS gives a wider spread of 39 feet (12 metres). Young trees have an upright, oval shape. Older trees form a broad, rounded crown, sometimes shaped like a mushroom. They may have several stems and low, level branches.

The bark stays smooth and ranges from gray to ashy beige. Slender young stems have fine hairs and a red-purple tint. They turn gray-brown in their second year. Leaves grow in opposite pairs, each with three leaflets. The leaflets have pointed tips and coarse teeth along their edges. Long, reddish stalks hold the leaves. Small white hair tufts occur beneath the leaves at vein joints. Young leaves can have a bronze tint. Summer foliage ranges from olive to dark green. Fall brings yellow and red, though some leaves drop while green.

Small yellow flowers open in spring, from March to April. They have a scent but make a modest display. The flowers hang in racemes about 0.33 feet (0.10 metres) long. Male and female flowers grow on separate trees. Female trees can form fruit without a nearby male tree. The fruits are paired, winged samaras. They start green and turn tan as they ripen. Each is about 0.08 feet (0.025 metres) long. UConn notes that many seeds lack embryos.

This maple grows best where summers stay cool. It accepts full sun but prefers some shade in hotter climates. Moist, fertile soil with good drainage suits it best. Acid soil is preferred, though the RHS also lists neutral and alkaline soils. A sheltered site suits the tree. Dry heat can cause early leaf drop. Sources place it in USDA zones 5–8 and RHS rating H6. It can serve as a specimen, shade tree, or understory tree. Other listed uses include hedges, street planting, and Asian-style gardens. It remains scarce in nurseries and gardens.

Sources report few serious pest or disease problems overall. Possible pests include aphids, scale insects, borers, caterpillars, and mites. Diseases can include Verticillium wilt, leaf spots, tar spot, and canker. Root rots, honey fungus, and leaf scorch are also listed.