SYNGENESIA. 185 



The character, common to the citrus tribe, is that of low ever- 

 green shrubs, with ovate, or oval lanceolate leaves, having 

 serrate, or entire margins, and glossy upper surfaces. So far 

 as known, the species are all either from Asia or China. The 

 species are only eight or ten, but the varieties are numeroua 

 There have been several works published on the Oranges, 

 among which that of Risso and Poiteau, printed at Paris, in 

 ] 818, is the most splendid. It is a folio volume, in which are 

 described 169 sorts of this fruit, of which 105 sorts are fig- 

 ured, and their culture, both in France and Italy, detailed at 

 great length. They are described as Sweet Oranges, of 

 which there are 42 sorts ; Bitter and Sour Oranges, 32 sorts ; 

 Bergamots, 5 sorts ; Limes, 8 sorts ; Shaddocks, 6 sorts ; 

 Lumes, 12 sorts ; Lemons, 46 sorts; Citrons, 17 sorts. 



All the sorts may be propagated by seeds, layers, cuttings, 

 engrafting, or inoculation. 



The unengrafted often have axillary spines, or thorns, 

 while the engrafted, or inoculated, are without this appen- 

 dage. The flowers are on peduncles, either axillary or ter- 

 minal. The fruits are a large berry, round or oblong, and 

 generally of a yellow color. The species are best distin- 

 guished by the petiole, which in the Orange and Shaddock, 

 is winged, but in the Citron, Lemon, and Lime, is naked. 

 The form of the fruit, although not quite constant, may also 

 serve as a means of distinction. In the Orange, and Shad- 

 dock, it is spherical, or nearly round, with a reddish yellow, or 

 orange colored rind. In the Lime, the fruit is also nearly 

 spherical, but a little oblong, and the color pale ; in the 

 Lemon, it is oblong, with a protuberance at the lower end, 

 and of a yellow color ; the Citron is oblong, with a very 

 thick rind. The flowers of the Citron and Lemon have ten 

 stamens, and those of the Orange more. In this genus it is 

 very difficult to determine what is a species, and what a va- 

 riety. 



CLASS XIX. SYNGENESIA. Stamens 5. Anthers 

 united by their edges. Orders 5. 



The name is from the Greek syn, together, and genesis, 

 origin, and means that the anthers grow together in a single 



What are the characters common to the citrus, or orange tribe ? How 

 may the orange tribe be propagated ? How may the orange and shaddock 

 trees be distinguished from the other species of this genus ? 



