Paulownia is a genus of 7 to 17 species of fast-growing deciduous hardwood trees (the exact count varies by taxonomic authority) placed in the family Paulowniaceae within the order Lamiales. The genus is native to east Asia and is most widespread across China, where it has been cultivated for centuries. It has been introduced as an ornamental tree across Europe and was brought to North America in 1844, where it has escaped cultivation in some regions and is considered invasive in parts of the United States.
Trees are large and vigorous, capable of growing more than 30 metres tall. The leaves are notably large, heart-shaped, and arranged in opposite decussate pairs; they emerge late in spring and fall late in autumn. The flowers appear before the leaves as showy pale violet to purple tubular blooms borne in terminal erect panicles 15–30 cm long, resembling foxglove flowers. The fruit is a woody capsule that persists on the tree through winter, each containing up to 2000 small winged seeds.
Paulownia is among the fastest-growing hardwood trees in the world. The timber is exceptionally light (density approximately 0.28 kg/L), straight-grained, warp-resistant, and dimensionally stable — qualities that have made it valued across east Asia for furniture, musical instrument soundboards, and traditional objects. In Japan the wood, known as kiri (桐), is fashioned into storage chests (tansu) and protective tomobako boxes for ceramics. It is important for the soundboards of stringed instruments including the guqin, guzheng, pipa, koto, and gayageum, and has more recently been adopted for electric guitar bodies and surfboard cores.
The genus holds deep cultural significance in Japan, where the stylised Paulownia flower forms the official government crest used by the Prime Minister and Cabinet. The tree is also associated with the month of December in the card game hanafuda.
Etymology
The genus name Paulownia honours Anna Pavlovna (1795–1865), queen consort of the Netherlands and daughter of Tsar Paul I of Russia. The original spelling was Pavlovnia, but the latinised form Paulownia has become standard. The common name "princess tree" refers to the same royal connection.
Distribution
Paulownia is native to east Asia and is most widespread in China, where it is a common roadside and ornamental tree. It has been introduced throughout Europe and North America; in some parts of the United States it has escaped cultivation onto disturbed ground and is regarded as invasive, though it is not considered invasive in Europe. Seeds spread readily after disturbances such as high-temperature wildfires, which create the sterile soils the species requires for establishment.
Ecology
Paulownia demands full sunlight and thrives in well-drained soils with reliable summer moisture. It is one of the fastest-growing trees in the world, capable of adding up to 6 metres in height in a single year when young. The tree is deep-rooting and late-leafing, producing a sparse canopy that allows enough light to reach understorey plants — a trait exploited in Chinese agroforestry systems where crops are grown beneath the trees. Each tree can produce up to 20 million tiny seeds annually, though successful germination is largely confined to sterile or recently disturbed soils.
Cultivation
Paulownia is grown commercially for timber, which can be harvested in as little as 5 years in optimised plantations. After felling, trees regenerate vigorously from the existing root system — a coppicing ability that has earned the genus the name "Phoenix tree." Commercial plantations typically propagate stock from root cuttings or seedlings rather than seed, as seeds are vulnerable to soil microbiota. The species performs well only in very well-drained soil with adequate summer rainfall or irrigation and is not suited to high water tables.
Cultural Uses
In China Paulownia (泡桐, pāotóng) is widely planted along roadsides and is integrated into agroforestry systems for its fodder leaves, nectar-rich flowers, and light but strong timber. In Japan the wood (kiri, 桐) is traditionally used for storage chests (tansu), protective tomobako boxes, clogs (geta), and charcoal for sketching. The Paulownia flower is the official crest of the Japanese Government, used by the Prime Minister and Cabinet. The tree is also one of the suits in the traditional Japanese card game hanafuda. Across east Asia the wood is prized for the soundboards of classical stringed instruments including the guqin, guzheng, pipa, koto, and gayageum.
History
Paulownia was first introduced to European gardens as an exotic ornamental and reached North America in 1844. The tree spread beyond cultivation partly through an unusual route: its lightweight capsules were used as packing material for goods shipped from east Asia, and discarded packing material established feral groves near major North American ports. It has not become a fixture of US ornamental gardens, partly because the persistent brown fruiting capsules are considered unattractive.
