Hydrangea (/ha?'dre?nd?i?/;common titles hydrangea or hortensia) is a genus of 70-75 types of flowering plant life indigenous to southern and eastern Asia (China, Japan, Korea, the Himalayas, and Indonesia) and the Americas. Undoubtedly the greatest types diversity is at eastern Asia, notably China, Japan, and Korea. Most are shrubs 1 to 3 meters large, however, many are small trees and shrubs, as well as others lianas reaching up to 30 m (98 feet) by climbing up trees. They could be either evergreen or deciduous, though the generally cultivated temperate types are all deciduous.Having been introduced to the Azores, H. macrophylla is currently very common, on Faial particularly, which is known as the "blue island" because of the vast number of hydrangeas present on the island.Life cycleHydrangea bouquets are created from planting season to late fall months; they expand in flowerheads (corymbs or panicles) most often at the ends of the stems.
Usually the flowerheads contain two types of flowers: small non-showy bouquets in the guts or interior of the flowerhead, and large, showy blossoms with large vibrant sepals (tepals). These showy blooms are often long in a ring, or to the surface of the small flowers. Crops in crazy populations have few to nothing of the showy bouquets typically, while cultivated hydrangeas have been bred and determined to have more of the larger type blooms.There are two flower arrangements in hydrangeas with Corymb style inflorescens, which includes the commonly grown "bigleaf hydrangea"--Hydrangea macrophylla. Mophead blooms are large spherical flowerheads resembling pom-poms or, as the name suggests, the head of an mop. On the other hand, lacecap flowers bear round, flat flowerheads with a center core of subdued, small flowers encircled by outer jewelry of larger blooms having showy tepals or sepals.
The plants of some rhododendrons and viburnums can show up, at first glance, comparable to those of some hydrangeas.Colors and dirt acidityIn most species the blooms are white, but in some kinds (notably H. macrophylla), can be blue, red, green, light crimson, or dark purple. In these species the colour is influenced by the occurrence of aluminum ions which are available or tied up depending after the garden soil pH. For H. h and macrophylla. serrata cultivars, the flower color can be determined by the relative acidity of the soil: an acidic soil (pH below 7), will have available aluminum ions and typically produce flowers that are blue to purple, whereas an alkaline soil (pH above 7) will tie up aluminum ions and result in pink or red flowers.
This is caused by a color change of the bloom pigments in the existence of aluminium ions which may be adopted into hyperaccumulating crops.[6] Decreasing the pH of potting soils or mixes usually does not change the bloom color to blue, because these soils have no aluminum ions. The capability to blue or green a hydrangea is influenced by the cultivar also. Some plants are selected for their ability to be blued, while some are bred and selected to be red, pink or white. The flower color of most other Hydrangea species is not afflicted by aluminum and cannot be changed or shifted. Hydrangeas also have a nickname called 'Change Rose'.