Hydrangea (/ha?'dre?nd?i?/;common labels hydrangea or hortensia) is a genus of 70-75 species of flowering crops local to southern and eastern Asia (China, Japan, Korea, the Himalayas, and Indonesia) and the Americas. Undoubtedly the greatest varieties diversity is in eastern Asia, china notably, Japan, and Korea. Most are shrubs 1 to 3 meters extra tall, but some are small trees, and more lianas achieving up to 30 m (98 ft) by climbing up trees. They can be either deciduous or evergreen, although cultivated temperate types are deciduous generally.Having been introduced to the Azores, H. macrophylla is currently very common, particularly on Faial, which is recognized as the "blue island" due to the vast number of hydrangeas present on the island.Life cycleHydrangea blooms are produced from early spring to late autumn; they grow in flowerheads (corymbs or panicles) frequently at the ends of the stems.
Usually the flowerheads contain two types of blossoms: small non-showy bouquets in the guts or interior of the flowerhead, and large, showy blossoms with large colourful sepals (tepals). These showy plants are often long in a ring, or to the surface of the tiny flowers. Plants in untamed populations routinely have few to none of them of the showy blooms, while cultivated hydrangeas have been bred and chosen to have more of the larger type plants.There are two flower arrangements in hydrangeas with Corymb style inflorescens, which includes the commonly grown "bigleaf hydrangea"--Hydrangea macrophylla. Mophead blooms are large rounded flowerheads resembling pom-poms or, as the name suggests, the comparative brain of a mop. In contrast, lacecap flowers bear round, flat flowerheads with a center core of subdued, small plants surrounded by outer bands of larger plants having showy tepals or sepals.
The blooms of some rhododendrons and viburnums can seem, at first glance, just like those of some hydrangeas.Colors and soil acidityIn most species the blossoms are white, but in some varieties (notably H. macrophylla), can be blue, red, pink, light crimson, or dark purple. In these types the colour is affected by the occurrence of aluminium ions which can be found or tangled up depending upon the ground pH. For H. macrophylla and H. serrata cultivars, the flower color can be dependant on the relative acidity of the soil: an acidic soil (pH below 7), will have available aluminum ions and produce flowers that are blue to purple typically, 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 bloom pigments in the existence of aluminium ions which is often taken up into hyperaccumulating vegetation.[6] Minimizing the pH of potting soils or mixes usually does not change the bloom color to blue, because these soils haven't any aluminum ions. The ability to blue or green a hydrangea is influenced by the cultivar also. Some plants are selected for his or her ability to be blued, while some are bred and selected to be red, white or pink. The flower color of all other Hydrangea species is not influenced by aluminum and cannot be changed or shifted. Hydrangeas likewise have a nickname called 'Change Rose'.


Hydrangea (/haɪˈdreɪndʒiə/;common names hydrangea or hortensia) is a genus of 70–75 species of flowering plants native to southern and eastern Asia (China, Japan, Korea, the Himalayas, and Indonesia) and the Americas. By far the greatest species diversity is in eastern Asia, notably China, Japan, and Korea. Most are shrubs 1 to 3 meters tall, but some are small trees, and others lianas reaching up to 30 m (98 ft) by climbing up trees. They can be either deciduous or evergreen, though the widely cultivated temperate species are all deciduous.Having been introduced to the Azores, H. macrophylla is now very common, particularly on Faial, which is known as the "blue island" due to the vast number of hydrangeas present on the island.Life cycleHydrangea flowers are produced from early spring to late autumn; they grow in flowerheads (corymbs or panicles) most often at the ends of the stems. Typically the flowerheads contain two types of flowers: small non-showy flowers in the center or interior of the flowerhead, and large, showy flowers with large colorful sepals (tepals). These showy flowers are often extended in a ring, or to the exterior of the small flowers. Plants in wild populations typically have few to none of the showy flowers, while cultivated hydrangeas have been bred and selected to have more of the larger type flowers.There are two flower arrangements in hydrangeas with Corymb style inflorescens, which includes the commonly grown "bigleaf hydrangea"—Hydrangea macrophylla. Mophead flowers are large round flowerheads resembling pom-poms or, as the name implies, the head of a mop. In contrast, lacecap flowers bear round, flat flowerheads with a center core of subdued, small flowers surrounded by outer rings of larger flowers having showy sepals or tepals. The flowers of some rhododendrons and viburnums can appear, at first glance, similar to those of some hydrangeas.Colors and soil acidityIn most species the flowers are white, but in some species (notably H. macrophylla), can be blue, red, pink, light purple, or dark purple. In these species the color is affected by the presence of aluminum ions which are available or tied up depending upon the soil pH. For H. macrophylla and H. 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 flower pigments in the presence of aluminium ions which can be taken up into hyperaccumulating plants.[6] Lowering the pH of potting soils or mixes usually does not change the flower color to blue, because these soils have no aluminum ions. The ability to blue or pink a hydrangea is also influenced by the cultivar. Some plants are selected for their ability to be blued, while others are bred and selected to be red, pink or white. The flower color of most other Hydrangea species is not affected by aluminum and cannot be changed or shifted. Hydrangeas also have a nickname called 'Change Rose'.