Paulownia is a genus of between 6-17 species (depending on taxonomic authority) of plants in the monogeneric family Paulowniaceae, related to and sometimes included in the Scrophulariaceae. They are native to much of China, south to northern Laos and Vietnam, and long cultivated elsewhere in eastern Asia, notably in Japan and Korea. They are deciduous trees 10-25 m tall, with large leaves 15-40 cm across, arranged in opposite pairs on the stem. The flowers are produced in early spring on panicles 10-30 cm long, with a tubular purple corolla resembling a foxglove flower. The fruit is a dry capsule, containing thousands of minute seeds. It is popular in its native China for reforestration, roadside planting and as an ornamental tree. It grows well in a wide variety of soil types, notably poor ones, but needs a lot of light and does not like a high water table. Paulownia timber is a pale whitish coloured wood with a straight grain. Its characteristics of rot resistance and a very high ignition point ensures the timber's popularity in the world market. Paulownia grown on plantations generally has widely spaced growth rings and is therefore much less valuable. The wood is also important in China, Korea, and Japan for making the soundboards of stringed musical instruments such as the guqin, pipa, koto, and kayagum.