Rhobs el Arsa - Citrus limon (L.) Burm

Rhobs al-Arsa (Citrus limon (L.) Burm. f.) is a very popular citrus fruit in Morocco.

Rhobs al-Arsa is Arabic for bread of the garden, or "Garden Loaf", probably referring to the forbidden fruit of the Garden of Eden (Jannah or hesperides), which according to some it was a citron or similar. There is also a well known hotel in Marrakesh, Morocco, named Riad Villa al-Arsa.

This citrus hybrid has many other names, like: Al-zanbu, Khoubs al-Arsa, Koubs al-Arsa, Kubbâd, Robs al-Arsa, Zamboa, Zanbo'a, Zemboua.

Evergreen shrub with the young green shoot, rounded leaves, green and shiny. Round fruit rather flat, with a small nipple at apex, inverted ring around nipple. Skin usually smooth, sometimes rough. Pulp is acidic and fruity, sweet and pleasant albedo, slightly bitter bark. Maturity in February or March. Cold hardiness -2 °C / 3 °C. Open pollinated seedling.

Although it is widely considered as a citron hybrid, its precise genetics are still not clear. Some assume it to be a hybrid between the true Moroccan citron as a male parent, and the sour orange as the female parent.

The University of California, Riverside Citrus Variety Collection have an accession named Koubs el-Arsa, which they received as seed from Marrakesh, Morocco, and it resembles a rough lemon. The USDA website also notes a resemblance to rough lemon, and suggests that it is a cross between citron or lemon, and a mandarin.

A 1970 study has suggested that it is a cross between the citron and lime.

A recent study has found that rhobs el arsa is clustering close to the Damas, Poncil and Kadu Mul citron hybrids, which are all closer to citron than the regular lemon, that itself is a citron hybrid.