322 



CITRON 



CITRUS 



during the summer all cultivation is stopped, and grass, 

 beggar-weed, or fleld-peas allowed to cover the ground, 

 preventing sunburning and providing a source of 

 humus so necessary in keeping up proper fert-lity and 

 texture of the sandy soil of Florida. 



E. N. Beasoner. 



CITRULLUS (from Pi7 ;■»«). Cunirbitdcew. The ge- 

 nus which includes tlic WattTiiirlon. Cogniaux, the 

 latest monographer (D(_'. M"n"f,'r. Phaner. 3), recog- 

 nizes three species, all of the Uld World, with the larg- 

 est dispersion in Africa. Plant monoecious, the two 

 kinds of fls. solitary in the axils of the Ivs.: fls. with a 

 short, bell-like calyx tube and a deeply 5-cleft, yel- 

 low c-orulia. C. vulgaris, Schrad., is the Watermelon 

 (wliii'h seel, iiati\"'- to tropical and south Africa. C. 

 Colocynthis, ."^chrad., is the Colocynth, extract fmm tlir 

 fruit of which furni-shes a well-known purgative drug. 

 It is native to the Mediterranean region and tropical 

 Africa. The fruit is small and globular, gourd-like, 

 smooth and partly colored, the flesh very bitter : Ivs. 

 deeply divided. L_ |j. g. 



ClXRUS (ancient name forCitron). Rutdceie. Orange. 

 Lemon, Citron, etc. Aromatic, glandular shrubs or 

 small trees, mostly thorny: Ivs. alternate, with more or 

 less winged petioles, compound, mainly unifoliolate 

 (appearing as a simple leaf but really compound, as 

 shown by the joint between the pe.tiole and lamina. 

 Pig. 475 ) , in one species trifoliolate : fl's. hermaphrodite ; 

 calyx cupulate, 3-5-toothed ; petals 4-8, linear-oblong, 

 thick, glandular, imbricated in the bud ; stamens nu- 

 merous, 20-60, occasionally only .'j ; fllaments more or 

 less united ; disk cushion-shaped ; ovary compound, 

 composed of 5 to many united carpels, with a single 

 style and stigma, and central axial placenta; ovules 4-8 

 in each carpel, arranged in two rows : fr. a round, ob- 

 long or pear-shaped berry with leathery rind, containing 

 numerous oil glands and juicy, aromatic pulp : seeds 

 white, exalbuminous, with leathery coats, frequently 

 containing 2 or more embryos. Native of tropical and 

 subtropical Asia. Several species are extensively culti- 

 vated aucl have given rise to numerous cultivated forms. 

 The so-called navel oranges have a second series of 

 cells developing in the center of the fr., this being an 

 incidental variation (Of. Fig. 476). See Citron, Lemon, 

 Lime, Orange, Pomelo. 



trifoliolafe, deciduous, with 

 r, -I lint,' lft<i.: fls, white, l~2in 

 tin' 'i.rt/ "f ' nrh h >!i, np,',inn/ In'fore the Ivs. appear 

 in. sprnni ; jutu/s sjiit t If /nti' : ovary and disk 

 hairy. 

 trifoli&ta, Linn. (C trlptera, Desf. JEgle sepiAria, 

 DC). Trifoliate Orange. Pigs. 477, 478, 479. A 

 small tree armed with very strong, stiff thorns, 1-1 J^ in. 

 long: fr. golden yellow, about the size of a walnut, cov- 

 ered with short hairs; pulp rather dry, sour and bitter. 

 Jap., and cult, widely in the United States. R.H. 1869, 

 p. 15; 1877, p. 73; 1885:516; 1886, p. 533. Gn. 46:980 

 and p. 273. Mn. 3 ; 101. - The fr. of the Trifoliate Orange 



PSEUDO-.«r.LE. - 



el/ipti.-ill.ilri 



475. Leaf of Orange. 



is worthless as a whole, but is sometimes used for pre- 

 serves. The plant is largely used for hedges, for which 

 it is well adapted, forming a close, compact growth that 

 nothing can penetrate. It is also used as a hardy stock 

 on which to bud certain oranges and lemons, particu- 

 larly the Satsuma and Kumquat. It is said to have the 

 effect of somewhat dwarfing the more robust orange va- 



rieties budded on it, and of making them more hardy by 

 rendering them dormant earlier in the fall, and retard- 

 ing them from starting early in the spring. The Tri- 

 foliate Orange is hardy as far north as Philadelphia and 

 New York. It is propagated by seeds, which are very 

 nmnerous. Hybrids have been made between this and 

 the common orange. The Trifoliate Orange is frequently 

 listed in trade catalogues under the names Limonia tri- 

 foliata and Triphasia aurantiola. These are tender. 



475. Normal orange on the right ; abnormal or navel orange 

 on the left, showing the adventitious cells in the center. 



tropical shrubs, and should not be confused with the 

 hardy G. trifoliata. 



AA. 'EiVCiTVXJS.—Lvs. unifoliolate, evergreen : petals 

 oblong: ovary and disk glabrous. 



Aur&ntium, Linn. (C vulgAris, Risso). Orange. 

 Figs. 476, 480. A small tree or shrub : young shoots light 

 green, glabrous ; Ivs. elliptical or ovate, acute, obtuse, 

 or acuminate ; petiole narrowly or broadly winged ; fls. 

 hermaphrodite, pure white: fr. oblate-spherical or ellip- 

 tical, not mamillate. 



Var. am&ra, Linn. {C. BigarAdia, Duham. ). Sour, 

 Bitter, or Seville Orange. Lvs. deep green, ovate, 

 pointed, very aromatic ; petiole broadly wing-mar- 

 gined: fls. white, sweet-scented: fr. round, dark orange, 

 frequently with tinge of red, very ammatic; rind some- 

 what rough; pulp sour and bitter. 'Southeastern Asia, 

 and cult, in tropical and subtropical regions throughout 

 the world.— There are very few cultivated sorts of this 

 variety or subspecies grown in the United States, and 

 of these only the two following are well known : Sour 

 ("sour orange") : Fr. deep orange or orange-red ; pulp 

 very sour. This is grown very extensively as a stock on 

 which to bud varieties of the sweet orange, lemon, 

 pomelo, etc. Very valuable as a stock because resistant 

 to the serious disease mal-di-gorama or foot-rot. — Bitter 

 Sweet : Fr. of same external appearance as the Sour 

 Orange but mildly acid and pleasant to the taste. Culti- 

 vated mainly for home use. The Sour Orange was evi- 

 dently inti-oduot-d into Fhiriila very early by the Span- 

 iards, and escapcil fVom coltivation, becoming esiab- 

 lished as a wild •^i>.-cits iicrt- and there throughout the 

 peninsular portion of tlie state. In this wild state it was 

 limited to moist lands near streams and lakes, in the so- 

 called hammocks ; and in some instances grew abun- 

 dantly among the larger forest trees, over areas of 100 

 acres or more. The fls. of this var. Amnni arc slightly 

 bitter, and are the oflicinal Folia aurii iitii or Fnlin citri 



vulgaris. An ethereal oil is manufacturoil fi- the fls.. 



young sprouts and unripe fr. The jileasant-smelling, 

 bitter Bigaradiaoil is taken from the rind of the ripe fr. 

 Large quantities of oil for perfume are manufactured 

 from the fls. in southern Prance. The fr. is used for 

 marmalade, and makes a very refreshing drink known in 

 Florida as "orangeade." 



Var. Berg&mia, Wight. & Am. Bergamot Orange. 

 A bush or small tree : Ivs. oblong ; petiole wing-mar- 



