Distylium racemosum

Distylium racemosum is the type species of the genus and the most tree-like of the isu trees, an evergreen member of the witch-hazel family, Hamamelidaceae. The genus name comes from the Greek for "two styles," for the paired styles at the center of each small flower, while the species epithet racemosum notes the short racemes along which those flowers are held.

Native to the subtropical forests, stream banks, and mountain slopes of eastern Asia, from southern Japan and the Ryukyu Islands through Korea's Jeju Island to southeastern China, Taiwan, and northern Vietnam, this is a slow-growing broadleaf evergreen that ranges from a large shrub to a sizeable tree. Glossy, leathery, dark green leaves and smooth reddish-brown bark give the plant a polished, year-round presence, and in the open the crown rounds and spreads with age.

In late winter and early spring, small petal-less flowers open in short racemes, showing as puffs of red stamens before giving way to capsule-like fruit. The bloom is quiet, best noticed up close, but arrives early enough to feed the first bees of the year. In Japan, where the tree can grow large, the fine-grained wood has long been valued for furniture and crafts, a reminder that this restrained ornamental has a working life as well.

Distylium racemosum remains uncommon in American gardens, though the tree was introduced well before the low, shrubby forms of the related Distylium myricoides that have lately become popular. According to Dirr's Manual of Woody Landscape Plants, the species may prove hardy as far north as zone 6. Give the plant room to develop as an evergreen specimen, a tall screen, or a clipped hedge, and pair with camellias, mahonia, and ferns in a woodland setting where the glossy foliage anchors the planting through every season.