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Citrus ID


Pummelos (Acidless)




Citrus aurantium [var.] grandis L.; C. aurantium [var.] decumana L.; C. decumana L.; Aurantium decumana (L.) Mill.; Citrus pamplemos Risso; C. maxima (Burm.) Merr. (sec. Swingle and Reece 1967)

Cultivar or taxon


Citrus maxima (Burm.) Merr. (sec. Mabberley 1997, Bayer et al. 2009; sec. Tanaka sec. Cottin 2002); Citrus grandis (L.) Osbeck (sec. Swingle and Reece 1967)



Hodgson (1967) noted that:

"The clone known in the United States (fig. 4-60) was introduced by the U.S. Department of Agriculture in 1930 and was received by the Citrus Research Center, Riverside, California, under the name Siamese Sweet (CES 2240).

The other non-acid clone is the Ama or Mikado buntan of Japan, which Y. Tanaka has described as the botanical variety dulcis (Tanaka 1948). From his description and illustration, the tree is indistinguishable from Siamese Sweet but the fruit is subglobose to spherical."



Crown compact or dense, not weeping. First-year twig surface pubescent; second- or third-year twig surface striate; thorns straight; prickles absent or not persistent. Petiole pubescent, length medium; wings narrow, medium or wide, adjoining the blade or tucking beneath blade. Leaflets one, margin entire or bluntly toothed, shade leaflet blades flat or weakly conduplicate, sun leaflet blades flat or weakly or strongly conduplicate. Leaflets not scented when crushed. Fruit as broad as long or longer than broad; rind green-yellow (6), yellow (7-10), yellow-orange (11), or orange (12); rind texture slightly rough (4-5); firmness leathery; navel absent; flesh yellow; taste acidless-sweet.

Hodgson (1967) provided the following additional notes on the group:

"Similar to the common pummelos in all respects except that they are virtually devoid of acid are the acidless or non-acid pummelos, a group analogous to the sugar oranges. Comparable analyses of acid content and sugar-acid ratios for a clone of this group and several common pummelos have been reported by Soost and Cameron (1961). Results were as follows: for an acidless clone, 0.08 to 0.10 per cent acid content and ratios of 126-151.3 to 1; for four common clones, 1.02 to 1.93 per cent acid content and ratios of 5.6-11.4 to 1."

"The tree is typical of the Siamese group in all respects—dwarf and drooping, with round-pointed leaves and densely pubescent twigs and new shoot growth. The fruits are oblate to broadly obovoid, with large, crisp, easily separable juice sacs lacking in juice, and insipidly sweet with a trace of bitterness. Siamese Sweet is of horticultural interest primarily as a curiosity and also because it is the seed parent of the recently released Chandler variety (Cameron and Soost, 1961)."



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.

Cameron, J.W., R.K. Soost, and F.O. Olson. 1964. Chimeral basis for color in pink and red grapefruit. Journal of Heredity 55(1): 23–28.

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.

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.

Tanaka, Y. 1948. An iconograph of Japanese Citrus fruits: a monographic study of species and varieties of Citrus fruits grown in Japan. Yokendo Co. Ltd., Tokyo. 2 vol.



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Citrus ID Edition 2
October, 2011