Cercidiphyllum is a genus containing two species of plants, both commonly called katsura. They are the sole members of the monotypic family Cercidiphyllaceae. The genus is native to Japan and China and unrelated to Cercis (redbuds). Description The type species, Cercidiphyllum japonicum, can reach in height, and is one of the largest hardwoods in Asia. The other species, Cercidiphyllum magnificum, is much smaller, rarely reaching over in height. Cercidiphyllum produces spurs along its twigs. These are short stems with closely spaced leaves. The foliage is dimorphic. According to a recent description "short shoots bear broadly cordate or reniform, palmately veined leaves with crenate margins; long shoots bear elliptic to broadly ovate leaves with entire or finely serrate margins." Leaf size varies from 3–8 cm long and 3–5.5 cm broad. The genus is dioecious, having separate male and female trees. The small inconspicuous flowers are produced in early spring and wind-pollinated; the fruit is a cluster of 2-4 small pods, each pod 1–2 cm long with numerous small, flattened and winged seeds. The fruits mature in autumn and release their seeds in autumn through winter. The leaves have a strong, sweet smell in the fall, described as caramel or Madeira cake-like. The smell comes from a combination of maltol and a sugary compound in the leaves and is strongest when they are brown. In German, Cercidiphyllum trees are named after their scent; or ("pie tree" or "gingerbread tree"). Nomenclature Katsura () is the Japanese name for the tree. The scientific name Cercidiphyllum refers to the close resemblance of the leaves to those of Cercis (redbuds); these two unrelated genera can however be distinguished easily as redbud leaves are alternate, not opposite. Species The two species are: Cercidiphyllum japonicum. Throughout the range of the genus. Typically a multi-stemmed tree to 40–45 m tall in the wild, though typically smaller in cultivation. Bark rough, furrowed. Leaves smaller, not over 4.5 cm long and 3.2 cm broad; stipules falling soon after leafing out in spring. Seed winged only at lower end. Plants from China were at one time separated as C. japonicum var. sinense, but no consistent difference between Japanese and Chinese origins has been found. Cercidiphyllum magnificum. Endemic to central Honshū, where it grows at higher altitudes than C. japonicum. A small tree, not more than 10 m tall. Bark smooth. Leaves larger, up to 8 cm long and 5.5 cm broad; stipules