Rhobs al-Arsa (''Citrus limon'' (L.) Burm. f.) is a very popular

citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is nati ...

fruit in

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria ...

Names

Rhobs al-Arsa is

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walte ...

for bread of the garden, or ''"Garden Loaf"''. This

hybrid has many other names, such as Al-zanbu, Khoubs al-Arsa, Koubs al-Arsa, Kubbâd, Robs al-Arsa, Zamboa, Zanbo'a, and Zemboua.

Description

The plant is an evergreen shrub with young green shoots, and rounded leaves that are green and shiny. The fruit is round and rather flat, with a small nipple at the apex, and an inverted ring around the nipple. Its skin is usually smooth. The pulp is acidic and fruity, with a sweet and pleasant albedo, slightly bitter bark. Maturity in February or March. It is cold-hardy to -2 °C / 3 °C, and is an open-pollinated seedling.

Genetics

The Rhobs al Arsa has long been viewed as a citron hybrid, though different cultivars have been suggested for the parents, for example, Moroccan citron as the male parent and sour orange as the female parent,

citron The citron (''Citrus medica''), historically cedrate, is a large fragrant citrus fruit with a thick rind. It is said to resemble a 'huge, rough lemon'. It is one of the original citrus fruits from which all other citrus types developed throu ...

lemon The lemon (''Citrus limon'') is a species of small evergreen trees in the flowering plant family Rutaceae, native to Asia, primarily Northeast India (Assam), Northern Myanmar or China. The tree's ellipsoidal yellow fruit is used for culin ...

and a

mandarin Mandarin or The Mandarin may refer to: Language * Mandarin Chinese, branch of Chinese originally spoken in northern parts of the country ** Standard Chinese or Modern Standard Mandarin, the official language of China ** Taiwanese Mandarin, Stand ...

, or citron and lime. Frutto pompia

Detailed genomic analysis showed Rhobs al Arsa to be highly similar to several cultivars of the '' Citrus limetta'', the limetta or Persian

sweet lime Sweet lemon and Sweet lime refer to groups of citrus hybrids that contain low acid pulp and juice. They are hybrids often similar to non-sweet lemons or limes, but with less citron parentage. Sweet limes and lemons are not sharply separated: ...

, and likely shared a common origin with them, arising from a cross between citron (''Citrus medica'') and sour orange (''Citrus'' × ''aurantium''). The common lemon and several other hybrids arose from distinct hybridization events involving the same two species. This proposed parentage was confirmed by a study of the native

Sardinia Sardinia ( ; it, Sardegna, label= Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label= Algherese and Catalan) is the second-largest island in the Mediterranean Sea, af ...

n citrus, the pompia (''C. medica tuberosa''), which was found to be genetically synonymous with the Rhobs el Arsa, both descended from the same hybrid, the product of a citron pollinating a sour orange, with the citron likely to be a native Italian variety such as the

Diamante A diamanté (also spelled diamante) is a glittering ornament, such as an artificial jewel (e.g. a rhinestone) or a sequin. Diamante may also refer to: Places Argentina * Diamante, Entre Ríos, a ''municipio'' in Diamante Department * Diama ...

or the Common Poncire citrons. Such citrons had been cultivated together with the sour orange around the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on th ...

after the introduction of the latter by Moors in the 8th century, and frequent spontaneous crosses are likely to have occurred. Another Mediterranean variety, the Poncire de Collioure, was likewise found to be synonymous with Rhobs el Arsa and pompia.

Notes

References

Agrumes Baches

Many photos of the fruit by Dr. Giuseppe

have one in their collection

{{citrus Agriculture in Morocco Arab cuisine Citron Citrus hybrids Moroccan cuisine