104 CHINESE ECONOMIC TREES 



C. limonia Osbeck. 

 Lemon. 



C. grandis Osbeck. 



(C. decumana Linna?us). 

 Grape Fruit and Pomelo. 



C. sinensis Osbeck. 

 Sweet orange. 



C. nobilis var deliciosa Swingle. 

 Mandarin Orange and Tangerine. 



PONCIRUS 



Trees or shrubs with green, shiny branchlets armed with stout, 

 straight thorns. Leaves deciduous, trifoliate; leaflets sessile, elliptic, 

 coriaceous, crenulate, glandular dotted. Flowers before the leaves, solitary, 

 sessile on the axil of the spine, 2.5 cm. across; sepals 4 or 5, small 

 deciduous; petals 4 or 5, white, obovate, narrowed at the base; stamens 

 8-l0 inserted on an anular disk, filaments free or partly connate, reddish 

 below; ovary globose, 6-8 celled. Fruit a small orange, densely pubescent. 



The genus differs from Cllrus with which it is sometimes united by 

 the trifoliate, deciduous leaves, by the flower buds which are developed in 

 the summer, and by other minor taxonomic characters. 



Poncirus trifoliata (L.) Rafinesque. 

 (Citrus trifoliata Linnaeus). 

 Kou Chu. Trifoliate Orange. 



A shrub or small tree, native of Northern China, widely cultivated. 

 The bitter fruit is used in medicine. The plant is frequently planted for 

 hedges, and often used as stock, upon which oranges and other Citrus 

 fruits are grafted. This species is a host to numerous insects and several 

 fungous diseases, rendering it undesirable for hedges or other forms of 

 ornamental planting. 



The flowers are very fragrant. 



EVODIA 



Tree or shrubs. Winter buds naked. Leaves opposite, simple, 

 trifoliate or pinnately compound; leaflets entire, punctate. Flowers 

 small, dioecious in axillary or terminal panicles or corymbs; sepals and 



