Royal

Synonyms

None

Cultivar or taxon

Citrus x aurantium L., pro sp. [Grapefruit Group] (sensu Mabberley 1997, Bayer et al. 2009); Citrus paradisi Macfad. (sensu Swingle and Reece 1967; sensu Tanaka sec. Cottin 2002)

Origin

Hodgson (1967) noted that: "Royal is said to have come originally from Cuba but was named and introduced in 1892 by the Royal Palm Nurseries of Oneco, Florida. It was grown commercially for several decades but has not been planted for many years."

Description

Crown compact or dense, not weeping. First-year twig surface glabrous; second- or third-year twig surface striate; thorns absent or not persistent; prickles absent or not persistent. Petiole glabrous, length medium; wings narrow, adjoining the blade. Leaflets one, margin bluntly toothed, shade leaflet blades weakly conduplicate, sun leaflet blades weakly or strongly conduplicate. Scent of crushed leaflets sweetly orange-like. Fruit as broad as long or longer than broad; rind green-yellow (6), yellow (7-10), yellow-orange (11), or orange (12); rind texture smooth (1-3) or slightly rough (4-5); firmness leathery; navel absent; flesh yellow; taste grapefruit-like.

Hodgson (1967) provided the following additional notes on the cultivar: "This Florida variety has a relatively small, nearly round, orange-yellow, seedy fruit of sweet flavor that lacks the typical grapefruit bitterness and aroma and is suggestive of sweet orange. While a distinctive variety, Royal has resemblances, notably in flavor and other respects, to such varieties as Triumph, Imperial, Mott and Leonardy, which suggests that they comprise a natural group and may possibly be grapefruit-orange hybrids (orangelos)."

References

Bayer, R.J., D.J. Mabberley, C. Morton, C.H. Miller, I.K. Sharma, B.E. Pfeil, S. Rich, R. Hitchcock, and S. Sykes. 2009. A molecular phylogeny of the orange subfamily (Rutaceae: Aurantioideae) using nine cpDNA sequences. American Journal of Botany 96: 668–685.

Cottin, R. 2002. Citrus of the World: A citrus directory. Version 2.0. France: SRA INRA-CIRAD.

Hodgson, R.W. 1967. Horticultural varieties of Citrus. In: Reuther, W., H.J. Webber, and L.D. Batchelor (eds.). The Citrus industry, rev. University of California Press. http://lib.ucr.edu/agnic/webber/Vol1/Chapter4.html.

Mabberley, D.J. 1997. A classification for edible Citrus (Rutaceae). Telopea 7: 167–172.

Swingle, W.T. and P.C. Reece. 1967. The botany of Citrus and its wild relatives. In: Reuther, W., H.J. Webber, and L.D. Batchelor (eds.). The Citrus industry. Ed. 2. Vol. I. University of California, Riverside. http://lib.ucr.edu/agnic/webber/Vol1/Chapter3.html.

Resources

Search for this cultivar in NCBI Entrez or NCBI Nucleotide

Additional information on this cultivar at University of California: Riverside Citrus Variety Collection