''Hydrangea arborescens'', commonly known as smooth hydrangea, wild hydrangea, sevenbark, or in some cases, sheep flower, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 th ...

in the

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

Hydrangeaceae. It is a small- to medium-sized, multi-stemmed,

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, aft ...

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 trees ...

up to tall that is

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 the eastern United States.

Description

The inflorescence is a corymb up to wide. Showy, sterile flowers are usually absent or if present they are usually less than 1 cm in diameter on the edge of the

panicles A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are o ...

. Flowering occurs May to July. Fruit is a ribbed, brown capsule about 2 mm long. Many are produced in October and persist through the winter. The leaves are large (8 to 18 cm long), opposite, serrated,

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

, and

. The lower leaf surface is glabrous or with inconspicuous fine hairs, appearing green;

trichome Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a pla ...

s of the lower surface are restricted to the midrib and major veins. The stem

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...

has a peculiar tendency to peel off in several successive thin layers with different colors, hence the common name "sevenbark". Smooth hydrangea can spread rapidly by

stolon In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external s ...

s to form colonies.

Taxonomy

At one time both ashy hydrangea (''

Hydrangea cinerea ''Hydrangea cinerea'', the ashy hydrangea or gray hydrangea, is a small to medium sized, deciduous shrub up to 3 m tall; its natural range is interior regions of the southeastern United States.Lance, Ron. 2004 Woody Plants of the southeastern Uni ...

'') and silverleaf hydrangea (''

Hydrangea radiata ''Hydrangea radiata'' is an attractive, deciduous shrub up to 3 m tall in the flowering plant family Hydrangeaceae. Its natural range is limited to the southern Appalachians, where it is fairly common.Lance, Ron. 2004 Woody Plants of the southea ...

'') were considered subspecies of smooth hydrangea.McClintock, E. 1957. A monograph of the genus ''Hydrangea''. Proceedings of the California Academy of Sciences 29: 147-256. However, most taxonomists now consider them to be separate species.Pilatowski, Ronald E. A taxonomic study of the ''Hydrangea arborescens'' complex. Castanea 47: 84-98.

Distribution and habitat

Smooth hydrangea is widely distributed across the eastern United States—from southern New York to the

panhandle A salient (also known as a panhandle or bootheel) is an elongated protrusion of a geopolitical entity, such as a subnational entity or a sovereign state. While similar to a peninsula in shape, a salient is most often not surrounded by water on ...

of Florida, west to eastern Oklahoma and southeastern Kansas. It is mainly found in moist soils under a hardwood forest canopy and is often common along woodland road banks and streams.Lance, Ron. 2004 Woody Plants of the southeastern United States: A winter guide. The University of Georgia Press. 456 p. It is common in the

Delaware River The Delaware River is a major river in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. From the meeting of its branches in Hancock (village), New York, Hancock, New York, the river flows for along the borders of N ...

Valley and in the

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

. It is a host plant of the hydrangea sphinx moth.

Uses

This attractive native shrub is often cultivated for ornamental use.Dirr, Michael A. hydrangeas for American gardens. Timber Press. 240 p. In the UK the

cultivar 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, ...

'Annabelle' has 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 (Nort ...

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 ...

. The cultivar 'Grandiflora' has flowers that resemble

snowball A snowball is a spherical object made from snow, usually created by scooping snow with the hands, and pressing the snow together to compact it into a ball. Snowballs are often used in games such as snowball fights. A snowball may also be a large ...

s, similar to ''

Viburnum plicatum ''Viburnum plicatum'' is a species of flowering plant in the family Adoxaceae (formerly Caprifoliaceae), native to mainland China, Korea, Japan, and Taiwan. The Latin specific epithet ''plicatum'' means “pleated”, referring to the texture of ...

''. Smooth hydrangea root was used medicinally by Native Americans, and later, by early settlers for treatment of kidney and bladder stones. It additionally has been marked as a pollinator plant, supporting and attracting bees and butterflies.

Gallery

File:Hydrangea arborescens annabelle.JPG, 'Annabelle' File:Hills-of-Snow Hydrangea arborescens 'Grandiflora' Flowers 2606px.jpg, 'Grandiflora' File:2020 year. Herbarium. Hydrangea arborescens. img-035.jpg, Leaf adaxial side. File:2020 year. Herbarium. Hydrangea arborescens. img-036.jpg, Leaf abaxial side.

References

External links

Cook, Will. Trees, shrubs, and woody vines of North Carolina. Wild Hydrangea (''Hydrangea arborescens'').
Large-format diagnostic photos and information

- Informative but non-scholarly essay on Hydrangea (Culture, History and Etymology).

{{Taxonbar, from=Q278173 arborescens Flora of the Northeastern United States Flora of the Southeastern United States Flora of the United States Flora of Alabama Natural history of the Great Smoky Mountains Plants used in traditional Native American medicine Plants described in 1753 Taxa named by Carl Linnaeus