Paulownia (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Paulownia Siebold & Zucc.

Family: Scrophulariaceae

Major species and synonyms

• Paulownia elongata S.Y. Hu.

• Paulownia fortunei (Seemann) Hemsley.

• Paulownia tomentosa (Thunb.) Steud., synonym: P. imperialis Sieb. & Zucc.

Vernacular names

• Philippines: kiri (general)
• Laos: s'o:k, s'o:z, s'o: phôk (northern).

Distribution

Native to India, northern Indo-China, China, Taiwan and Japan; introduced into Thailand and the Philippines, occasionally cultivated as an ornamental elsewhere in South-East Asia.

Uses

The wood yields excellent charcoal used for high class fireworks and gunpowder. It is also used for beams and poles. The lightweight timber is highly valued in Taiwan and Japan, and suitable for wood work, musical instruments, sandals, delicate furniture, linings, cabinets, badminton rackets, and also for fishing net floats, boxes and crates. In China, P. tomentosa is planted for erosion control and intercropped with wheat. Wood and bark are reported to have astringent properties. Several species are used for reforestation in Thailand, and their use is being promoted in East Asia. P. tomentosa was introduced into the Philippines for wood producing plantations. P. fortunei seems capable of cleaning air polluted with chlorine.

Observations

• Small deciduous trees up to 20 m tall.
• Leaves opposite, ovate to broadly ovate, cordate at base, entire or slightly 3-5-lobed, usually tomentose below.
• Flowers in 3-5-flowered cymes; calyx campanulate, 5-lobed; corolla zygomorphic, shortly 5-lobed, slightly 2-lipped; stamens 4.
• Fruit a dehiscent capsule.
• Seed winged.

The trees are easy to propagate by means of cuttings. Their growth is very rapid: mean annual diameter increment is 6.5 cm, and mean annual height increment is 1.72 m. The wood is comparatively soft, white or reddish-brown, and has a beautiful grain. Its air-dry density is about 320 kg/m³.

Selected sources

• Binua, T.M. & Acosta, R.T., 1978. Field notes on kiri. Canopy International 4(6): 6.
• Flore du Cambodge, du Laos et du Viêt-nam [Flora of Cambodia, Laos and Vietnam] (various editors), 1960-. Volume 1-. Muséum National d'Histoire Naturelle, Laboratoire de Phanérogamie, Paris, France.
• Nair, P.K.R., 1993. An introduction to agroforestry. Kluwer Academic Publishers, Dordrecht, the Netherlands. 499 pp.
• National Academy of Sciences, 1980, 1983. Firewood crops: Shrub and tree species for energy production. 2 volumes. National Academy Press, Washington, D.C., United States. 237, 92 pp.
• Wealth of India (various editors), 1948-1976. A dictionary of Indian raw materials and industrial products: raw materials. 11 volumes. Publications and Information Directorate, Council of Scientific and Industrial Research, New Delhi, India. 4441 pp.

Authors

• M.S.M. Sosef & L.J.G. van der Maesen