A CALAMONDIN HYBRID
GLEN CITRANGEDIN
The calamondin has been utilized in a number of hybrids, the most promising of them being one in which it was pollinated with pollen of the Willits citrange. This citrange, which has been previously described, is itself a hybrid, resulting from pollinating the Japanese trifoliate orange (Poncirus trifoliata) with pollen of the common sweet orange (Citrus sinensis). The citranges as a class are the hardiest of all evergreen citrus varieties or hybrids, but the fruit usually retains an objectionable quantity of musky oil, derived from the trifoliate parent, that necessitates special precautions in using the rather acid fruits for " ade " or preserves. Most of the hybrids in which the citrange has been utilized have traces of this flavor — much reduced, however, as in the Thomas ville citrangequat, a hybrid of the oval kumquat (Fortunella margarita) and the Willits citrange. By hybridizing the Willits citrange with the calamondin, however, a fruit has been produced that is fully as hardy as the citrange parent but entirely free from the pungent oil usually associated with hybrids of trifoliate orange ancestry. The tree, however, so closely resembles the common calamondin that some doubt might be raised as to the hybrid nature of the plant but for the occurrence of trifoliate leaves, especially in the juvenile stages, combined with much greater hardiness and greater vigor of growth, as compared with the ordinary calamondin.
This hybrid was the result of a cross-pollination made by the senior writer in the spring of 1909 at Glen St. Mary, Fla. Mature trees
have been fruiting with great regularity at Glen St. Mary for some years past and have survived freezes that severely injured the ordinary calamondin and the limequat. More than 100 miles farther north, at McKae, Ga., this hybrid has also fruited well, and the fruit has been reported as acceptable at the local soda fountains for use in preparing "limeade," which can scarcely be distinguished from the true limeade.
As this fruit originated at Glen St. Mary, where it has long been fruiting, it is proposed to call it the Glen citrangedin.
Technical description. — Fruit somewhat variable in size, oblate-spheroid, 1%
to 1% inches in transverse diameter by 1 to iy± inches high, small per-
sistent calyx set in slight depression, minute nipple at pistil end; color deep
reddish orange (Ridgway, cadmium orange) ; rind thin and firm (one-
eighth inch in thickness), not as free peeling as the calamondin and some-
what coarser, smooth and glossy, except for slight indentations due to
numerous minute oil-cell depressions; segments 6 to 8, separating easily;
small solid core ; pulp juicy, tender, and translucent, very sharply acid but with-
out trace of the repugnant oil usually encountered in hybrids of the trifoliate
orange, color of pulp orange yellow (Ridgway cadmium yellow) ; seeds small
and plump, 3 to 5, some fruits seedless. Tree evergreen, of vigorous upright
habit, highly ornamental, especially when bearing a crop of bright-colored fruits ;
leaves usually unifoliate, occasional bifoliate and trifoliate leaves appearing,
dark green, glossy, 1% to 2^4 inches in length, long-pointed oval, petiole nar-
rowly winged and long in comparison with leaf size.
The tree has the habit, more pronounced than in the true calamondin, of
bearing its fruit in clusters at the ends of long slender branches, bending the
tree over with the weight of the fruit.
In regions too cold for growing the limequat or the ordinary calamondin with safety, this hardy fruit, the Glen citrangedin, offers
an attractive and useful substitute. It is, of course, chiefly of service in preparing "ades" and in flavoring, much as lemons or limes are used. When not intended for immediate use, the fruit should be picked in the yellow or green-yellow stage rather than when red, as the small, fully ripe fruits tend to shrivel rather rapidly when held at ordinary storage temperature.
The tree is more or less everbearing, although the bulk of the fruit matures in the late summer and fall months. Owing to its small
size, the fruit freezes at temperatures only slightly below freezing, so it can not be held on the trees over winter in cold sections. Most of the trees thus far fruiting have been budded on the trifoliate-orange stock, and this doubtless has added to their hardiness. The tree should be grown on this stock or on the hybrid citrange in the colder sections of the Gulf coast and coastal-plains area of the South.
Like the true calamondin, this new fruit has value as an ornamental when grown as a dwarf or potted plant.
The Glen citrangedin, obtained by hybridizing the Willits citrange with the calamondin, is a remarkable new acid fruit which combines to a large extent the extreme hardiness of the citrange parent with the high acidity and excellent flavor of the calamondin. It has been grown successfully as far north as McRae (latitude 32°), in southern Georgia, and can endure more winter cold than any other acid fruit of good quality yet studied.
Unlike the citrange, the Glen citrangedin has a sharp acid flavor without a trace of the repellent bitter flavor carried by oil globules
in the interior of the pulp vesicles of the citrange. It is not only an excellent "ade" fruit for home use and for local markets, but
also has high ornamental value if grown as a dwarf or potted plant.
On account of its extreme hardiness it should be tested throughout the warmer parts of the Gulf coast and also in southern and south-eastern Georgia, southern Texas, and possibly in the cooler irrigated valleys of Arizona where lemons, limes, and even limequats do not succeed.
New Citrus Hybrids, United States Department of Africulture, Circular No. 181, August 1931