Citrus.] XVII. RUTACE^E. 51 



may eventually alter the number of species, and modify their limits and char- 

 acters. These researches should, however, comprise not only the apparently in- 

 digenous forms, and those cultivated in Europe and India, but equally the large 

 variety of Oranges cultivated in China, Japan, and Polynesia. 



A few introductory remarks regarding the classification of this genus may not 

 be out of place. Linnaeus established two species, C. medica, with linear peti- 

 oles, comprising the Lime, Lemon, and Citron ; C. Aurantium, with winged 

 petioles, comprising the sweet and bitter Orange and the Shaddock. From these 

 Willdehow separated the Shaddock, C. decumana ; and Roxburgh, Fl. Ind. iii. 

 390, added C. acida, under which name he described the acid Lemons and Limes, 

 and the sweet Limes of India with winged petiole, which therefore could not 

 be classed under C. medica of Linnaeus. C. inermis, the small unarmed Orange 

 of China, he added as a separate species. About the time that Roxburgh wrote 

 his ' Flora Indica/ the history and classification of the cultivated Oranges was 

 the subject of careful researches by two botanists in the south of Europe. 

 Georges Gallesio, Sous Prefet of Savona, published in 1811 a small octavo vol- 

 ume (Traite du Citrus) containing the results of most valuable studies and ob- 

 servations made by him in the district of Finale, between Nice and Genoa, on 

 the Riviera di Ponente. Gallesio establishes 4 species (Citron, Lemon, sweet 

 and bitter Orange), to which he refers, either as varieties or as hybrids, all forms 

 known to him. A few years later in 1813 A. Risso, Professor of ;Natural 

 Sciences at the Lyceum of Nice, published in the 20th volume of the ' Annales 

 du Museum d'Histoire Naturelle,' his " Memoire sur l'histoire naturelle des 

 Orangers, cultives dans le Departement des Alpes Maritimes." His classification 

 agrees in the main with that of Gallesio, but he adds the sweet Lime {C. Limetta) 

 as a 5th species : and in a subsequent work which appeared in 1819, with mag- 

 nificent illustrations (Risso et Poiteau Histoire Naturelle des Orangers), 8 types 

 or races are described : 1. C. Aurantium, the sweet Orange ; 2. C. Bigaradia, 

 the bitter Orange ; 3. C. Bergamia, the Bergamot ; 4. C. Limetta, the sweet 

 Lime (with white flowers) ; 5. C. decumoma, the Shaddock ; 6. C. Lumia, the 

 sweet Lemon (flowers tinged with red) ; 7. C. Limonum, the Lemon ; and 8. C. 

 medica, the Citron. This classification has been adopted in many standard 

 works. A. Decandolle, however, in his ' Geographie Botanique raisonneV (1855), 

 871, expresses his opinion that the principal forms may be reduced to 3 species, 

 C. medica, C. Limonum, and C. Aurantium, with the addition, as a doubtful 

 species, of the Shaddock. This arrangement is carried out in Lowe, ' Flora of 

 Madeira' (1868), 71 ; but he adds C. nohilis, Lour., comprising the sweet Oranges 

 with loose skin (the Tangerine and Mandarin Orange), as a separate species. 

 Grisebach, in his ' West Indian Flora' (1864), 132, reverts to the three original 

 species, C. medica, Aurantium, and decumana ; and this is the arrangement 

 which 1 have here adopted, with some modification of the specific characters. 

 I desire, however, to state at the outset, that the characters here set forth do not 

 hold good in the case of all cultivated kinds classed under these three species. 

 Some of the intermediate forms may be hybrids ; and besides, it is more than 

 probable that we have not yet arrived at the correct classification of this genus. 

 The present arrangement, however, seems the most convenient to guide and 

 facilitate further researches in India on this interesting subject. 



1. C. medica, Linn. The Citron, Lemon, sweet and acid Lime. Com- 

 prises C. medica, Limonum, and Lumia of Risso and Poiteau. 



Shrubs, sometimes trees, generally bearing flowers and fruit at all, or at 

 most, seasons of the year. Young shoots glabrous, purple. Leaves glab- 

 rous, 3-6 in. long, oblong elliptic ovate or ovate-lanceolate ; petioles naked 

 or winged. Flowers white, generally tinged with red, small or middle- 

 sized, often unisexual ; stamens 20-40. Fruit ovoid, oblong or globose, 



