Kalopanax is a genus that consists of one species of deciduous tree, the Kalopanax septemlobus, belonging to the Araliaceae family. Also referred to as Kalopanax pictus, this tree is more commonly known as the prickly castor-oil tree, castor aralia, or castor-leaved aralia. The last two common names are due to the presence of spikes in its bark, which are reminiscent of Aralia elata and Aralia spinosa. Native to China, Japan, and Korea, it was introduced to North America in the 19th century. This tree is also found in eastern Russia.
It can grow up to 88 feet (27 m) in height in the wild, though it reaches just 59 feet (18 m) under cultivation. Kalopanax is a flowering tree that is in full bloom from July to August. The tree's white clustered flowers turn into globose bluish-black fruits with two flat seeds inside. These fruits ripen in September and October and attract birds and squirrels.
This tree has long-stalked and palmate leaves with five to seven finely toothed acuminate lobes resembling the leaves of some maples and the sweetgum. Prickly and stout, the branches of this tree spread out wide, providing dense shade. This attribute has made it popular as an ornamental and shade tree. It has been used in golf courses, parks, and school campuses. Kalopanax can be planted in tree lawns as long as they are more than 6 feet (1.8 m) wide, and it can also do well when planted along streets as long as there is enough space for root expansion.
While it is mainly grown in the West for ornamental purposes, Kalopanax is also valued in the East for its medicinal uses. In traditional Chinese medicine, the dried bark is utilized for its anti-fungal properties. The root is used as an expectorant, while the leaves are used to make tea for aiding digestion or for increasing appetite. Modern studies reveal the nutritional content of the leaves, in which high levels of calcium, iron, and zinc are found. This is why Kalopanax leaves are an ingredient in dietary supplements as well.
Kalopanax tends to be easy to grow. Propagation is usually done by seed and should be grown in full sun. It thrives in deep and moist yet well-drained soil. Drought is tolerated once the plant is established, but before that it should receive a good amount of moisture. There are no pests that are known to live on this tree, although one must take note of its invasive potential.