562 A TEXT-BOOK OF BOTANY. 



is a shrub or small tree with broadly oval, acuminate leaves, red 

 or nearly black drupes, and flowers and fruits several weeks 

 earlier than P. serotina. 



Primus Amygdalus is a small tree resembling somewhat the 

 peach tree. The leaves are lanceolate, serrate ; the flowers are 

 rose-colored, and the fruit is a dehiscent drupe in which the 

 leathery sarcocarp separates from the endocarp, which latter, with 

 the seed which it encloses, constitutes the edible almond of the 

 market. The kernels of some of the seeds are quite bitter (bitter 

 almonds), and some are bland and free from bitterness. By a 

 process of selection plants yielding the latter are now extensively 

 cultivated in sub-tropical and warm-temperate regions, and yield 

 the sweet or Jordan almond of the market. In Turkestan some 

 of the almonds have a smooth endocarp. 



A glucosidal substance having the properties of amygdalin is 

 found in the buds, leaves, bark and seeds, more especially the 

 latter, of some members of the following genera : Primus, Sorbus 

 (mountain ash), Cotoneaster, Amelanchier, and Eriobotyra (E. 

 japonica or Japanese medlar). 



Prunus domestica yields the French plum or prune of com- 

 merce. The leaves are ovate or ovate-lanceolate, dentate, and 

 pubescent on the lower surface. The flowers are greenish-white, 

 with a hairy peduncle. The fruit is a drupe, with a black or 

 bluish-black epicarp, a brownish sarcocarp, and a hard, oval, 

 smooth and flattened endocarp. 



The endocarps of the members ol tne genus Prunus vary greatly. 

 The endocarp in the apricot (P. Armeniaca} is quite smooth, as is 

 also that of the cherry (P. Cerasus) ; in the peach (Prunus Per- 

 sica) it is reticulate. The bark of Pyrus Toringo yields a yellow 

 coloring principle known in Japan as " dzaini." It also contains 

 a white, crystalline glucoside (toringin), and pyrus-quercitrin, the 

 latter forming yellow needles and on hydrolysis yields quercetin 

 and rhamnose. The bark is also used to adulterate licorice, gentian 

 and other drugs in the powdered form. 



The apple (Pyrus Malus) , the pear (Pyrus communis}, and the 

 quince (Cydonia vulgaris) are inferior fruits known as pomes, 

 the fleshy part developing from the torus and persistent calyx, 

 the core being composed of the united carpels. The edible fruits 



