''Hydrangea macrophylla'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Hydrangeaceae Hydrangeaceae is a family of flowering plants in the order Cornales, with a wide distribution in Asia and North America, and locally in southeastern Europe. Description The genera are characterised by leaves in opposite pairs (rarely whorled ...

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

to Japan. It is a

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from tree ...

growing to tall by broad with large heads of pink or blue flowers in summer and autumn. Common names include bigleaf hydrangea, French hydrangea, lacecap hydrangea, mophead hydrangea, penny mac and hortensia. It is widely cultivated in many parts of the world in many climates. It is not to be confused with '' H. aspera'' 'Macrophylla'.

Description

The term ''macrophylla'' means large- or long-leaved. The opposite leaves can grow to in length. They are simple, membranous, orbicular to elliptic and acuminate. They are generally serrated. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are forme ...

of ''Hydrangea macrophylla'' is a

corymb Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficial ...

, with all flowers placed in a plane or hemisphere, or even a whole sphere in cultivated forms. Two distinct types of flowers can be identified: central, non-ornamental,

pentamerous Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a ...

ones, and peripheral, ornamental,

tetramerous Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a w ...

ones. The latter have sterile pistils with fertile stamen. The four sepals of decorative flowers have colors ranging from pale pink to red fuchsia purple to blue. The non-decorative flowers have five small greenish sepals and five small petals. Flowering begins in early summer and lasts until early winter. The fruit is a subglobose capsule.

Distribution and habitat

''Hydrangea macrophylla'' is native to East Asia. It is reported from seaside habitats as well as mountains in Japan, from Honshu southwards. This species has naturalized in China, Korea, Siberia, New Zealand and the Americas. It is an invasive species in the

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and

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archipelagos.

Colors and soil acidity

''Hydrangea macrophylla'' blooms can be blue, red, pink, light purple, or dark purple. The color is affected by

soil pH Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the ne ...

. An acidic soil (pH below 7) will usually produce flower color closer to blue, whereas an alkaline soil (pH above 7) will produce flowers more pink.This is caused by a color change of the

flower pigment Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biol ...

s in the presence of

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

ions which can be taken up into hyperaccumulating plants.

Landscaping

In climates where ''Hydrangea macrophylla'' flowers, place in a mixed shrub border or at the back of a flower bed. Its rich foliage and large size make it a wonderful background for white or light colored flowers, even tall growing perennials and annuals. In warm climates ''H. macrophylla'' is good for adding a splash of early summer color to shady areas and

woodland garden A woodland garden is a garden or section of a garden that includes large trees and is laid out so as to appear as more or less natural woodland, though it is often actually an artificial creation. Typically it includes plantings of flowering shr ...

s. Minimal pruning is recommended for most prolific flowering. Flowers are easily air dried and are long lasting. While ''Hydrangea macrophylla'' is not considered a particularly difficult plant to grow, it may fail to flower. This may be due to cold winter damage to the flower buds, not getting enough sunlight, too much nitrogen fertilizer, or pruning at the wrong time of year. ''H. macrophylla'' forms flower buds in late summer. As a result, pruning in late summer, fall or winter could remove potential flowers.

Chemistry

Phyllodulcin,

hydrangenol Hydrangenol is a dihydroisocoumarin. It can be found in ''Hydrangea macrophylla ''Hydrangea macrophylla'' is a species of flowering plant in the family Hydrangeaceae, native to Japan. It is a deciduous shrub growing to tall by broad with lar ...

, and their 8-O-glucosides, and thunberginols A and F can be found in ''H. macrophylla''.

Thunberginol B Thunberginol B is an isocoumarin found in ''Hydrangeae Dulcis Folium'', the processed leaves of ''Hydrangea macrophylla ''Hydrangea macrophylla'' is a species of flowering plant in the family Hydrangeaceae, native to Japan. It is a deciduous sh ...

, the dihydroisocoumarins

thunberginol C Thunberginol C is a dihydroisocoumarin found in ''Hydrangeae Dulcis Folium'', the processed leaves of ''Hydrangea macrophylla ''Hydrangea macrophylla'' is a species of flowering plant in the family Hydrangeaceae, native to Japan. It is a decidu ...

, D and E, the dihydroisocoumarin glycosides

thunberginol G Thunberginol G is a dihydroisocoumarin found in ''Hydrangeae Dulcis Folium'', the processed leaves of ''Hydrangea macrophylla ''Hydrangea macrophylla'' is a species of flowering plant in the family Hydrangeaceae, native to Japan. It is a decidu ...

3'-O-glucoside and (−)-

4'-O-glucoside and four

kaempferol Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol, a type of flavonoid, found in a variety of plants and plant-derived foods including kale, beans, tea, spinach, and broccoli. Kaempferol is a yellow crystalline solid with a meltin ...

and

quercetin Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor ...

oligoglycosides can be found in ''Hydrangeae Dulcis Folium'', the processed leaves of ''H. macrophylla'' var. ''thunbergii''. The leaves also contain the stilbenoid

hydrangeic acid Hydrangeic acid is a stilbenoid found in the leaves of '' Hydrangea macrophylla''.Hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii as a new type of anti-diabetic compound. Hailong Zhang, Hisashi Matsuda, Chihiro ...

. The various colors, such as red, mauve, purple, violet and blue, in ''H. macrophylla'' are developed from one simple anthocyanin, delphinidin 3-glucoside (

myrtillin Myrtillin is an anthocyanin. It is the 3-glucoside of delphinidin. It can be found in all green plants, most abundantly in blackcurrant, blueberry, huckleberry, bilberry leaves and in various myrtles, roselle plants, and ''Centella asiatica'' pl ...

), which forms complexes with metal ions called metalloanthocyanins.

Lunularic acid Lunularic acid is a dihydrostilbenoid found in the liverwort ''Lunularia cruciata'' and in the roots of '' Hydrangea macrophylla''. A lunularic acid decarboxylase has been detected from the liverwort ''Conocephalum conicum ''Conocephalum conic ...

, lunularin, 3,4′-dihydroxystilbene and a glycoside of lunularic acid have been found in the roots of ''H. macrophylla''. Hydrangine is another name for the coumarin umbelliferone, and may be responsible for the possible toxicity of the plant.

Possible uses

Amacha is a Japanese beverage made from fermented leaves of ''Hydrangea macrophylla'' var. ''thunbergii''. ''Hydrangeae Dulcis Folium'' is a drug made from the fermented and dried leaves of ''H. macrophylla var. thunbergii'' with possible antiallergic and antimicrobial properties. It also has a hepatoprotective activity by suppression of D-galactosamine-induced liver injury in vitro and in vivo. ''Hydrangea macrophylla'' is included in the

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n Fire Service's list of low

flammability A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...

plants, indicating that it is suitable for growing within a building protection zone. Leaf extracts of ''Hydrangea macrophylla'' are being investigated as a possible source of new chemical compounds with antimalarial activity.

Hydrangeic acid Hydrangeic acid is a stilbenoid found in the leaves of '' Hydrangea macrophylla''.Hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii as a new type of anti-diabetic compound. Hailong Zhang, Hisashi Matsuda, Chihiro ...

from the leaves is being investigated as a possible anti-diabetic drug as it significantly lowered blood glucose, triglyceride, and free fatty acid levels in laboratory animals.

Cultivars

The two main types of ''H. macrophylla'' cultivars are called "mophead" and "lacecap". Some popular hydrangea

cultivars A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

(those marked have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

) include: *'All Summer Beauty'; cold-hardy,

floriferous {{Short pages monitor