GEMANIALES. 



541 



Ailanthus glanduhsus, the Tree of Heaven, a native of China, is com- 

 monly planted in the United States as a shade tree. Its wood is valu- 

 ahle in cabinet-making. 



Order Butacese.— The Rue Family. Shrubs and trees, rarely herbs, 

 ■with glandular-punctate heavy-scented foliage ; leaves generally com- 

 pound and alternate ; stamens generally distinct. The order as here 

 considered includes 650 known species, widely distributed in tropical 



Fias. 503-505. — Illustrations op Citrus Aurantium. 



Pia. 503. 



Fig. 504. Pia. 506. 



Hg. 602.— Section of flower. Magnified. 

 Fig. 508.— Part of andicecium. Magnifled. 

 Fig. 504. — Flower diagram. 

 Fig. 605.— Calyx and ovary. Magnifled. 



and temperate climates. Seven tribes, most of which were former!/ 

 •considered to be orders, are recognized byBentham and Hooker. 



Tribe A.urantiece, with actinomorphic, monoclinous flowers, 

 baccate (berry-like) fruits, and seeds without endosperm. (Figs. 502-5.) 



Citrus AuraTdium, the Sweet Orange, is an Indian tree, now grown 

 throughout all warm countries of the world for its well-known fruits. 



C. lAmonum, the Lemon, is a native of Northern India, now widely 

 •distributed. It was introduced into Europe during the Crusades. 



Other species of Citrus yield valuable fruits, as C. meAica, the Citron ; 

 0. lAmetta, the Lime ; C decumana, the Shaddock ; C. Bigaradia, the 

 Seville or Bitter Orange, etc. , etc. 



The hard yellow wood of the Orange is valued for inlaying 



