Cercidiphyllaceae Plant Family

About the Cercidiphyllaceae or Katsura Tree Family

Cercidiphyllaceae is a small family of flowering plants that includes only one genus, Cercidiphyllum. The family is known for its deciduous trees, which are renowned for their unique scent and beautiful heart- leaves. These plants are native to East Asia and have a long history of use in traditional medicine and as ornamental trees in gardens and urban landscapes. Despite their limited distribution, the Cercidiphyllaceae family is an important component of many ecosystems, providing habitat, food sources, and other ecological benefits.

Taxonomy and Classification

Cercidiphyllaceae is a family of flowering plants in the order Saxifragales. The family includes only one genus, Cercidiphyllum, which consists of approximately 7- species of deciduous trees. The genus Cercidiphyllum is further divided into two subgenera based on differences in leaf morphology and other characteristics. There are no known related families or plant groups closely related to Cercidiphyllaceae. However, some taxonomic studies have suggested that the family may be closely related to the Tetracentraceae family, which contains only one genus, Tetracentron.

Morphology and Characteristics

Plants within the Cercidiphyllaceae family are deciduous trees that range in size from small shrubs to large trees up to 30 meters tall. They are known for their distinctive sweet scent, which arises from the leaves and bark of these plants. The leaves of Cercidiphyllum species are generally heart- and alternate along the stem. They are typically simple, serrated, and arranged in an opposite pattern. The flowers of these plants are small and inconspicuous, with no petals or sepals, and are arranged in dense clusters. The fruit of Cercidiphyllum is a dry, winged samara containing one or two seeds. One notable feature of this family is the presence of compounds called diflavonoids, which are unique to Cercidiphyllum species and have been used as a chemotaxonomic marker for the family.

Distribution and Habitat

Cercidiphyllum species are native to East Asia, including China, Japan, and Korea. They are found in a variety of habitats, including forests, mountain slopes, and riverbanks. The different species within the genus have varying distributions, with some species being more widespread than others. For example, Cercidiphyllum japonicum is found throughout much of Japan and parts of China, while Cercidiphyllum magnificum is restricted to just a few locations in China. These plants thrive in regions with mild to cool climates and are often cultivated as ornamental trees in temperate regions around the world.

Economic and Ecological Importance

Cercidiphyllaceae species have both economic and ecological importance. These trees are often cultivated as ornamentals for their attractive foliage, distinctive scent, and showy autumn coloration. They are also used in traditional medicine to treat a variety of ailments such as diarrhea, rheumatism, and hypertension. In addition, Cercidiphyllum wood is valued for its strength and durability, making it a popular choice for furniture, flooring, and other wood products.

Ecologically, these plants play an important role in their native ecosystems. They provide food and habitat for many species of insects, birds, and mammals. The leaves and bark of some species contain compounds that may have medicinal properties, and some have been used in traditional Chinese medicine for centuries. Finally, the trees in this family contribute to biodiversity and help maintain healthy forest ecosystems.

Notable Species

Some notable species within the Cercidiphyllaceae family include:

  1. Cercidiphyllum japonicum: Also known as Katsura tree, this deciduous tree is native to Japan and produces attractive, heart- leaves that turn yellow, orange, and red in autumn. The leaves of this tree emit a distinctive sweet scent when crushed.

  2. Cercidiphyllum magnificum: This rare species is found only in a few locations in China. It is a large deciduous tree with an attractive bark that peels away in large flakes. The leaves of this tree are also heart- but larger than those of other species in the genus.

  3. Cercidiphyllum praecox: Native to China, this tree is known for its early flowering, producing small, inconspicuous flowers in winter or early spring before the leaves emerge. The leaves of this tree are smaller and more slender than those of other species in the genus.

  4. Cercidiphyllum japonicum 'Pendulum': This cultivar of C. japonicum is known for its weeping habit, producing cascading branches covered in heart- leaves that turn shades of yellow, orange, and red in autumn. This tree is often grown as a specimen plant in gardens and landscapes.

All of these species are valued for their ornamental qualities and are commonly cultivated in gardens and arboreta around the world. Some Cercidiphyllum species, particularly C. japonicum, have been overexploited in the wild for timber and medicinal use, which has led to declines in their populations and increased conservation efforts.