''Exochorda'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

s 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 ...

Rosaceae, native to China and central Asia (Turkestan). They are used as ornamental plants with the common name pearl bush, or pearlbush. Numerous

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

have been described on the basis of differing appearance and geographical separation, but a systematic studyGao Fangyou. 1998. Exochorda: ''five species or one?: a biosystematic study of the Rosaceous genus'' Exochorda. Wageningen University Dissertation published as a book. revealed that the different types are closely related and probably all descended from a single species that formerly had a wide distribution that has been fragmented by habitat loss. As a single species the correct name is '' E. racemosa''.

Description

They are

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, a ...

shrubs growing tall. The leaves are paddle-shaped oval, long, with an entire or bluntly serrated margin. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...

s are white, with five petals, produced in spring on the ends of the branches. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

is a dry coccetum consisting of five fused

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...

s, which split to release the flattened

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s. Lindley wrote in the original description of the genus "The free placentary chords external to the carpels have suggested the name of the genus."

Cultivation

A valuable garden

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two diff ...

is known as ''E.'' × ''macrantha'' C.K.Schneid. or ''Exochorda'' 'The Bride'. Lemoine's catalog of 1904 C. K. Schneider, translated by Wikipedia">Camillo_Karl_Schneider.html" ;"title="s cited by Camillo Karl Schneider">C. K. Schneider, translated by Wikipediastated "We obtained this hybrid by fertilizing ''E. alberti'' with pollen from ''E. grandiflora''. The clusters of flowers which terminate each shoot, are erect or horizontal, each one with 8 to 10 large flowers, well opened and unfolded, snow white. This new shrub has the vigorous growth of ''E. grandiflora''. As an isolated specimen the effect is magnificent." This plant has gained the Royal Horticultural Society's Award of Garden Merit.

Gallery

Image:Pearlbush Exochorda racemosa Leaf Stalk 2000px.jpg, Leaves Image:Exochorda x macrantha flowers.jpg, ''E.'' × ''macrantha'' 'The bride', flowers Image:Exochorda the bride E.jpg, Young fruit Image:Exochorda ripe fruit.jpg, Fully open fruit after the seeds have dispersed

References

External links

Flora of China: ''Exochorda''
*Huxley, A. (1992). ''The New RHS Dictionary of Gardening'' 2: 274. Macmillan. *''Trees & Shrubs'', Botanica, 1987, pg. 373. *http://www.bbc.co.uk/gardening/plants/plant_finder/plant_pages/310.shtml BBC Gardening Plant Finder {{Taxonbar, from=Q137339 Exochordeae Monotypic Rosaceae genera