530 SYSTEMATIC BOTANY. 



cold and temperate regions of the northern hemisphere. The 

 order Eosacese comprises about 1000 species, of which about one 

 half belong to the sub-order Eosege. 



Properties and Uses. — Tlie plants of the order are principally 

 remarkable for their astringency, and for their succulent edible 

 fruits. The seeds, flowers, leaves, and young shoots of many of 

 the AmygdalecB and Poviecs, when moistened with water yield 

 Hydrocyanic acid; hence the parts of such plants are then 

 poisonous. All other Eosacese are entirely devoid of poisonous 

 properties. 



Sub-Order 1. Chrys(ibalane^.— Many plants of this sub-order produce 

 edible drupaceous fruits. 



Chrysobalanus. — The fruit of C. Icaeo is edible. It is known in the West 

 Indies under the name of the Cocoa-plum. The fruit of C. luteus is also 

 eaten in Sieira Leone. The root, bark, and leaves of C. Icaco are employed 

 in Brazil as a remedy in diaiThoea and similar diseases. 



Parinarium. — P. excel sum also yields an edible fruit, which is known in 

 Sierra Leone under the name of the Rough-skinned or Gray Plum. The 

 kernels of the P. campestre and P. montanum are also reputed to resemble 

 the Almond in flavour. 



Sub-Order 2, Amygdale^. or Drupace^.— This sub-order is remarkable 

 from the parts of many of its plants yielding when moistened with water, 

 hydrocyanic acid. Their barks also fi-equently possess astringent and febri- 

 fugal properties, and yield a kind of gum : while many, again, have edible 

 fruits and seeds. 



Amygdalus. A. communis is the Almond-tree, of which there are two 

 varieties, namely, the A. communis, var. dulcis, and the A. communis, var. 

 amara. The seeds of the former are known as Sweet Almonds ; those of 

 the latter, as Bitter Almonds. The Almond-tree is a native of Syi'ia and many 

 other parts of Asia, and also of Barbary and Northern Africa ; it is also ex- 

 tensively cultivated in the southern parts of Europe. Sweet Almonds yield 

 by expression a fixed oil commonly known as Oil of Almonds. They also 

 contain sugar, gum, and a substance called vegetable albumen, Synaptase, 

 or Emulsin. The cake left after the expression of the oil, when dried and 

 powdered, is known under the name of Almond-powder. Bitter Almonds 

 yield a similar oil by expression. They also contain Emulsin, and, in addi- 

 tion to the other ordinary constituents of Sweet Almonds, a nitrogenous 

 substance called Amygdaline. When bitter almonds are moistened with 

 water, the Emulsin and Amj'gdaline mutually react upon each other and 

 foim a volatile oil containing hydrocyanic acid, and which is known as the 

 Essential Oil of Bitter Almonds. The presence of hydrocyanic acid renders 

 this oil very poisonous, but this is not the case when the acid is separated 

 fi-om it. Bitter Almonds and their essential oil are extensively em])loyed 

 for flavouring by the cook and confectioner, and also for scenting soap and 

 for other purposes by the perfimier. The cake left after expressing the oil 

 is frequently used for fattening pigs and for other purposes. A. persica is 

 the Peach-tree of our gardens, and a variety of the same species produces 

 the Nectarine. The flowers of A . persica have been employed as a veiini- 

 fuge, and the leaves for flavouring, and as a venntfuge. The kernels may 

 be used for the same purposes as the Bitter Almond. All these parts, as 

 weU as the bark, possess poisonous properties owing to the formation of 

 hydrocyanic acid. 



Prunus. P. domestica and its varieties produce the well-known fruits 

 called Plums, Greengages, and Damsons. When dried plums are termed 

 Prunes or French Plums. P. spinosa is the common Sloe or Blackthorn, and 

 P. institia, the Bullace. P. armeniaca is the Apricot. The barks of P. spi- 

 nosa and/*. Cocomilia have febrifugal properties. The leaves of P. spinosa are 

 sonietimes used for adulterating the black tea of China. A mixture consisting 

 of the leaves of P. spinosa and those of Fragaria collina, or F. vesca, in the 



