''Rosa'' × ''alba'', the white rose of York, is a hybrid

rose A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

of unknown parentage that has been cultivated in Europe since ancient times. It may have originally been grown mainly for the sweet scent of the flowers, but is now also used as a winter-hardy garden shrub. Cultivated forms have white or pink flowers, and most have many petals. Hybrid cultivars have also been produced with red or yellow flowers.

Description and distribution

''Rosa'' × ''alba'' plants are tall

shrub A shrub or 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 by their multiple ...

s with arching stems and bluish-green leaves. They bloom only in mid summer. They are extremely cold hardy and disease resistant, hence they are used to create new varieties for

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a continental climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of ...

s like northern Scandinavia and Canada. These magnificent shrubs can withstand shade and semishade, and are easily found abandoned in semi wild situations. In

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

and

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

the French bred 'Minette' has been considered a wild rose called ''R.'' × ''suonum'' (Mustialanruusu). The Mustiala rose belongs to the Finns' tradition of roses "and is unknown outside the Nordic countries, although in 1819 it was bred in France".(in Finnish) article
"Rosa 'Minette' / mustialaros, nordisk ros" via Sanoma News Oy Found alba roses are very common in

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

; some may be local variations, but some could be old cultivars waiting to be renamed.

Parentage hypotheses

''Rosa'' × ''alba'' is

hexaploid Polyploidy is a condition in which the cells of an organism have more than two paired sets of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one fro ...

, with six sets of chromosomes in each cell, which means that it interbreeds only rarely with the more common diploid, tetraploid, and pentaploid roses. Maskew and Primavesi concluded in 2005 that a 1993 suggestion by Graham and Primavesi that it was derived by chromosome duplication from a triploid offspring of ''R. arvensis'' (diploid) and ''R. gallica'' (tetraploid) had been mistaken. ''R. alba'' shares some nuclear DNA sequences with ''R. canina'' and may be derived from hybridization between that species and ''R. gallica''.

Alba cultivars

Cultivars of ''Rosa'' × ''alba'' that are still grown include: * Rosa 'Alba Foliacea' * Rosa 'Alba Maxima' * Rosa 'Alba Semi-plena' * Rosa 'Alba' Suaveolens' * Rosa 'Amélia' * Rosa 'Belle Amour' * Rosa 'Blanche de Belgique' * Rosa 'Céleste' * Rosa 'Chloris' * Rosa 'Félicité Parmentier' * Rosa 'Great Maiden's Blush' * Rosa 'Jeanne d'Arc' * Rosa 'Königin von Dänemark' * Rosa 'Mme Legras de St Germain' Mmeplantier

Hybrid cultivars include: * Rosa 'Mme Plantier', an old rose with feathery sepals and cream flowers fading to white * Rosa 'Crimson Blush', with red flowers, introduced 1988 * Rosa 'Lemon Blush', with pale yellow flowers, introduced 1988 * Rosa 'Morning Blush', white with pink and red edges, introduced 1988 * Rosa 'Royal Blush', with pale pink flowers, introduced 1988 * Rosa 'Tender Blush', with pale apricot flowers, introduced 1988

References

External links

* {{DEFAULTSORT:Rosa alba

alba ''Alba'' ( , ) is the Scottish Gaelic name for Scotland. It is also, in English-language historiography, used to refer to the polity of Picts and Scots united in the ninth century as the Kingdom of Alba, until it developed into the Kingd ...

Hybrid plants

Description and distribution

Parentage hypotheses

Alba cultivars

See also

References

External links