Hydrangea (common names Hydrangea and Hortensia) is a genus of about 70-75 species of flowering plants native to southern and eastern Asia (from Japan to China, the Himalaya and Indonesia) and North and South America. The flowers are extremely common in the Azores Islands of Portugal, particularly on Faial Island, which is known as the "blue island" due to the vast number of hydrangeas present on the island. By far the greatest species diversity is in eastern Asia, notably China and Japan. Most are shrubs 1-3 m tall, but some are small trees, and others lianas reaching up to 30 m by climbing up trees. They can be either deciduous or evergreen, though the widely cultivated temperate species are all deciduous.