780 



CITRULLUS 



CITRUS 



CITRULLUS (diminutive of Citrus, said to be in 

 allusion to the shape of fruits and color of flesh resem- 

 bling those characters in fruits of the orange or citron). 

 Cucurbitdcese. Annual or perennial tendril-bearing herbs 

 of three or four species, one yielding the watermelon 

 and one the colocynth. 



Climbing or long-trailing, hispid or rough, with 2-3- 

 parted tendrils, often with a strong odor: Ivs. alter- 



972. Citropsis Schweinfurthii. ( X M) 



nate, petiolate, mostly round-cordate in general out- 

 line, deeply 3-5-lobed, and the divisions often again 

 lobed, and the segms. commonly obtuse: fls. monoe- 

 cious, solitary and peduncled in the If .-axils, the corollas 

 5-lobed; stamens 3, included and united or cohering 

 by the anthers, and rudiments of stamens in the pis- 

 tillate fls.; pistil 1, the ovary ovoid or globose, bearing 

 a short style and 3-lobed stigma: fr. a globular pepo, 

 morphologically 3-celled, usually smooth and with a 

 hard rind. Trop. Afr. and Asia, 2 of the species now 

 widely distributed in warm and tropical countries. 



vulg&ris, Schrad. WATERMELON (see Melon, for cul- 

 ture). Annual, glabrous or pubescent: Ivs. not rough, 

 either deeply or moderately divided, the sinuses open 

 and obtuse: fr. in the wild state from the size of an 

 apple to that of a man's head, sweet or slightly bitter. 

 Trop. and S. Afr. When the fr. is sweet and edible 

 (C. Cdffer, Schrad.), it is the watermelon, or "kaffir 

 watermelon" of S. Afr.; when bitter (C. amarus, 

 Schrad.), it is the "bitter-apple" of S. Afr. The fr. now 

 varies widely in cult., in size, season, shape and quality. 

 The soft pink flesh is much prized in its natural state 

 for eating. A form with hard and inedible white flesh 

 is known as "citron," and the rind is used for the mak- 

 ing of preserves (as is the rind of the true citron) . 



Colocynthis, Schrad. (Colocynthis officinalis, Schrad. 

 Cucumis Colocynthis, Linn.). COLOCYNTH. BITTER- 

 APPLE. Perennial (in the wild), the st. angular and 

 rough: Ivs. rough, 2-4 in. long, 3- or 7-lobed, the mid- 

 dle lobe sometimes ovate, the sinuses open and the If. 

 in general form like that of C. vulgaris: ovary villous: fr. 

 globose, green-and-yellow variegated, about 3-4 in. 

 diam., intensely bitter; seeds small (J^in. or less long), 

 smooth. Trop. Asia and Afr., now widely distributed in 



Afr. and the Medit. region. The dried frs. are used in 

 medicine (as purgative), being imported from Turkey 

 and Spain. Sometimes cult in this country as a curios- 

 ity or in collections of economic plants; culture for 

 officinal purposes has been attempted in New Mex., but 

 the frs., although larger than the official product, are 

 reported to be less active. L jj g 



CITRUS (ancient name of a fragrant African wood, 

 afterward transferred to the Citron). Rutacese. 

 CITRON. LEMON. ORANGE. Small evergreen, more or 

 less spiny trees or shrubs, grown for their edible fruits, 

 and also attractive in foliage and flower. 



Leaves glandular-dotted, persistent, apparently 

 simple (in reality unifoliate compound Ivs.), borne on 

 more or less winged or margined petioles, which are 

 usually articulated with the blade and at their attach- 

 ment to the twig: spines usually present, borne singly 

 at the side of the bud in the axils of the Ivs. : fls. clus- 

 tered or rarely solitary in the axils of the Ivs., or in 

 small lateral or terminal cymes or panicles, white or 

 pinkish purple in the bud ; petals 5 (rarely 4 or 6) thick, 

 strap-shaped, not clawed at the base, imbricated; 

 stamens numerous (16-60, usually 20-40) at least four 

 times as many as the petals, polyadelphous, cohering 

 toward the bases in a few bundles; ovary 8-15-celled, 

 with a prominent usually deciduous style containing as 

 many tubes as there are cells in the ovary: fr. a hes- 

 peridium, globose, oval or oblate-spheroid, the segms. 

 filled with juicy pulp composed of stalked pulp-vesicles; 

 seeds 1-8 in a cell, oval or oblong, M~Min. long, with 

 a pergameneous testa and thick fleshy cotyledons, 

 usually with adventive embryos arising as buds from the 

 nucellar tissue of the mother plant. Natives of Trop. 

 and Subtrop. Asia and the Malayan Archipelago. 

 Half a dozen species are commonly cult, and have given 

 rise to very many varieties as well as numerous hybrids, 

 making the delimitation of the species exceedingly 

 difficult. See Citrange, Citron, Etrog, Grapefruit, Lemon, 

 Lime, Limequat, Orange, Pomelo, Tangelo. 



The nomenclature here followed is based on the 

 writer's treatment of the species of Citrus in "Plantse 

 Wilsonianse." The fewest possible number of changes 

 have been made consistent with presenting a clear 

 account of the genus. A careful study of Citrus and 

 the genera most nearly related to it has shown that 

 the trifoliate orange differs in so many and such 

 important characters that it seems necessary to recog- 

 nize it as a separate genus (Pondrus). The same is 

 true of the kumquats and the Australian limes. 



aurantifolia, 3. 

 Aurantium, 4, 5, 6. 

 Bigaradia, 5. 

 decumana, 4. 

 deliciosa, 7. 

 digitata, 1. 

 grandis, 4. 



INDEX. 



ichangensis, 9. 

 limetta, 3. 

 Limonia, 2. 

 Limonium, 2. 

 Medica, 1. 

 mitis, 8. 



myrtifolia, 5. 

 nobilis, 7. 

 sarcodactylia. 1. 

 sinensis, 6. 

 unshiu, 7. 

 vulgaris, 5. 



KEY TO THE SPECIES. 



A. Winged petiole nearly as large as the 

 blade of the If.: seeds very large, thick: 

 fr. rough, oval, lemon-yellow when 



ripe: fls. solitary 9. ichangensis 



AA. Winged petiole much smaller than the 

 blade of the Ivs.: seeds small or me- 

 dium sized: fls. usually in clusters. 

 B. Lvs. apparently not jointed between 

 blade and petiole, oblong-serrate; 

 petiole wingless: fl.-buds ' tinted 

 reddish: fr. with a very thick peel, 



fragrant, pulp acid 1- Medica 



BB. Lvs. with an obvious joint between the 

 blade and petiole, crenate: peel thin 

 or only moderately thick. 

 C. Fl.-buds tinted reddish on outside: 

 petioles merely margined: Ivs. 

 crenate: frs. oval, more or less 

 apiculate 2. Limonia 



