Hydrangea (/ha?'dre?nd?i?/;common labels hydrangea or hortensia) is a genus of 70-75 kinds of flowering vegetation native to southern and eastern Asia (China, Japan, Korea, the Himalayas, and Indonesia) and the Americas. By far the greatest types diversity is within eastern Asia, china notably, Japan, and Korea. The majority are shrubs 1 to 3 meters high, however, many are small trees, among others lianas reaching up to 30 m (98 foot) by climbing up trees. They could be either evergreen or deciduous, although cultivated temperate species are all deciduous widely.Having been introduced to the Azores, H. macrophylla is very common now, on Faial particularly, which is recognized as the "blue island" due to the multitude of hydrangeas present on the island.Life cycleHydrangea plants are produced from planting season to late fall months; they develop in flowerheads (corymbs or panicles) frequently at the ends of the stems.
Usually the flowerheads contain two types of blooms: small non-showy bouquets in the guts or interior of the flowerhead, and large, showy plants with large colourful sepals (tepals). These showy blooms are extended in a wedding ring often, or to the surface of the small flowers. Crops in outdoors populations routinely have few to nothing of the showy flowers, while cultivated hydrangeas have been selected and bred to have significantly more of the bigger type bouquets.There are two flower arrangements in hydrangeas with Corymb style inflorescens, which includes the commonly grown "bigleaf hydrangea"--Hydrangea macrophylla. Mophead plants are large circular flowerheads resembling pom-poms or, as the name means, the mind of an mop. In contrast, lacecap flowers bear round, flat flowerheads with a center core of subdued, small blossoms ornamented by outer bands of much larger blooms having showy tepals or sepals.
The bouquets of some viburnums and rhododendrons can appear, initially, much like those of some hydrangeas.Colors and land acidityIn most varieties the blossoms are white, however in some species (notably H. macrophylla), can be blue, red, red, light purple, or dark crimson. In these varieties the colour is influenced by the existence of lightweight aluminum ions which can be found or tangled up depending after the ground 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 the effect of a color change of the blossom pigments in the presence of aluminium ions that can be adopted into hyperaccumulating crops.[6] Reducing the pH of potting soils or mixes usually will not change the bloom color to blue, because these soils have no aluminum ions. The ability 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'.