Djerook Sinonja (sec. Cottin 2002)
Citrus x aurantium L., pro sp. [Grapefruit Group] X Citrus x aurantium L., pro sp. [Sweet Orange Group] (sensu Mabberley 2004, Bayer et al. 2009); Citrus paradisi Macfad. x Citrus sinensis (L.) Osbeck (sensu Hodgson 1967; sensu Tanaka sec. Cottin 2002)
Hodgson (1967) noted that: "According to Moscoso (1958)...this fruit first came to his attention in 1956 as a wild seedling tree in the mountainous Angeles and Caguanas rural section of Utuado municipality. Subsequently, however, other seedling trees were found in isolated areas of the coffee zone. The parentage of Chironja is unknown, but it is thought to be a natural orangelo of local origin. The fruit has attracted interest and limited quantities are available in the principal local market."
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, medium or wide, adjoining the blade or tucking beneath blade. Leaflets one, margin bluntly toothed, shade leaflet blades flat or 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), or yellow-orange (11); rind texture slightly rough (4-5) or medium rough (6-7); firmness leathery; navel absent; flesh orange or yellow; taste grapefruit-like.
Hodgson (1967) provided the following additional notes on the cultivar:
"Fruit large (grapefruit size), broadly obovoid to pyriform: low neck or broad somewhat furrowed collar; few-seeded, seeds strongly polyembryonic. Rind medium-thin, smooth, moderately adherent but readily peelable; color bright yellow at maturity. Segments about 10; axis medium-large and semi-open. Flesh color yellowish-orange; tender, very juicy; flavor mild, lacking the bitterness of the grapefruit. Midseason in maturity and fruit holds well on tree.
Tree vigorous, large, and grapefruit-like; leaves broadly winged, somewhat cupped, and margins irregularly undulate. Fruits usually borne singly rather than in clusters characteristic of grapefruit."
Hodgson (1967) has additionally noted that: "Chironja recently came to notice in Puerto Rico and exhibits resemblances to both the orange and grapefruit, particularly to the latter. The name represents a combination of Chi(na), the local term used for the sweet orange, and (to)ronja, the Spanish word for grapefruit."
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. 2004. Citrus (Rutaceae): A review of recent advances in etymology, systematics and medical applications. Blumea 49: 481–498.
Moscoso, C.G. 1958. The Puerto Rican chironja—new all-purpose citrus fruit. Economic Botany 12: 87–94.
Search for this cultivar in NCBI Entrez
Additional information on this cultivar at University of California: Riverside Citrus Variety Collection
Citrus ID Edition 2
October, 2011
idtools.org
