A U R A N T I A C E JE. 



165 



Citrus. — Linn. 



Calyx 3-5-cleft, urceolate. Petals 3-8 oblong-. Stamens 20-60 ; filaments dilated at 

 base, polyadelphous ; anthers oblong-. Style I, terete. Fruit baccate, 7-12-celled. 



The species of this genus are very difficult to define, as from long cultiva- 

 tion they present innumerable varieties, boih in the leaves and fruit. They 

 are all trees or large shrubs with axillary spines. The leaves are all simple, 

 but as they are articulated with the petiole, it is evident that they are in reality 

 pinnate leaves reduced to the terminal leaflet. The fullest account of this 

 genus has been given by Risso, in an elaborate work on those cultivated in 

 the south of Europe. 



1. C. aurantium, Risso. — Leaves oval, elongated, acuminate ; petiole, more or less 

 dilated and winged. Flowers white, larg-e. Fruit globose, depressed ; skin rough ; 

 pulp sweet. 



Risso, Ann. Mus. xx. 181 ; De Candolle, Prod. i. 539; Lindley, Flor. 

 Med. 163. 



Common Names. — Orange ; Sweet Orange. 



Foreign Names. — Oranger, Fr> ; Arancio dolce, It. ; Pomeranzin, Ger. 



Description. — A mid- 

 die-sized evergreen tree, Fig. 92. 



much branched, and co- 

 vered with a greenish- 

 brown bark. Branches 

 generally with axillary 

 spines. Leaves alternate, 

 entire, of a shining green 

 colour, nearly elliptical, 

 acuminated and furnished 

 with winged footstalks. 

 The flowers are large, 

 white, and very fragrant, 

 and arise from the smaller 

 branches on simple and 

 divided peduncles. The 

 calyx is saucer-shaped, 

 and divided into five 

 pointed sepals. The pe- 

 tals are five, oblong, con- 

 cave, and beset with small 

 glands. The stamens are 

 twenty or more, united 

 at their base into several 

 sets, and support vertical, 

 yellow anthers. The ova- 

 ry is superior, roundish, 

 bearing a cylindrical style 

 with a globose stigma. 

 The fruit is globose, de- 

 pressed, of a reddish-yel- 

 low colour externally, and 

 internally divided into se- 

 veral cells, filled with a 

 mucilaginous pulp ; each 

 cell containing from two 

 to four white seeds, with a 

 cartilaginous skin. The 

 rind is composed of two 

 distinct layers, the outer, 

 thin and glandular ; the inner, thick, white and spongy. 



C. Aurantium. 

 1. Flower. 2. A set of Stamens. 3. Section of Ovary. 

 Fruit. 



4. Section of 



