258 SYSTEMATIC BOTANY. 



tion of the stamens is almost imperceptible. Sanc/uisorbefS are merely a 

 degraded form of Rosece, where the petals and one or other set of essential 

 organs are abortive in each flower. 



Distribution. There are about a thousand species. The Chrysobalancce 

 are chiefly found in tropical America and Africa, more rarely in Asia : the 

 Drupaccce are mostly natives of the temperate parts of the Northern 

 Hemisphere, but are widely spread in cultivation ; the Pomece also belong 

 to the Northern Hemisphere ; most of the Rosece and Sanyuisorbece belong 

 to temperate and cold climates, but a few are tropical. 



Qualities and Uses. The succulent fruits of many of the plants form the 

 most striking feature of this Order. Various parts of the structure, but 

 especially the seeds, yield much hydrocyanic acid in the Suborders Dru- 

 pacece and Pomece. (The bark and root of almost all are bitter and astrin- 

 gent, owing to the presence of tannin. Drupacece commonly contain a 

 gum (resembling Gum Arabic) in the sap. This gum is the result of 

 a pathological change in the tissues. 



Most of the Chrysobalanece have stone-fruits ; that of C. Icaco (West 

 Indies) is eaten under the name of Cocoa-plum. 



Among the Drupacece we have the fruits : Almond (Amyydalus com- 

 munis) ; the Peach and Nectarine (A.persica) ; the Plum in all its varieties, 

 such as Greengages, Bullaces, Damsons, &c. (Prunus domestica, spinosa, 

 and varieties) ; the Apricot (Primus armeniaca) j the Cherry (Cerasus 

 avium, &c.). Cerasus Lauro-cerasus is the common " Laurel " or Cherry- 

 laurel of our shrubberies, C. lusitanica the Portugal Laurel. Many of 

 these plants contain a considerable quantity of amygdaline, causing the 

 formation of prussic acid when they are bruised. This gives to the seeds 

 of the Bitter variety of Almond, and to all other seeds in this Suborder, a 

 poisonous property, which exists also to a great extent in the leaves and 

 shoots of the Cherry-laurel, the flowers of the Almond, Peach, &c. The 

 seeds also contain a fixed oil, which may be obtained by expression ; and 

 that of the Sweet variety of the Almond is devoid o'f amyc/daline, and 

 thus harmless. The bark of Prunus serotina is used medicinally in inter- 

 mittent fevers. Pomece have succulent fruits, such as the Apple, Pear 

 (Pyrus Mains and communis), Quince (Cydonia vttlgaris), Medlar (Mes- 

 pilus ffermanica), &c., which have been brought into the edible condition 

 by cultivation ; when wild, they are mostly austere, like those of the 

 Hawthorn (Cratceyus), of the Mountain Ash (Pyrus Aucuparia), &c. 

 The seeds contain amygdaliue, and therefore yield prussic acid ; as do also 

 the flowers, bark, and root of the Mountain Ash. Quince-seeds are 

 valuable for the mucilage they contain. 



The Rosece yield edible fruits, such as the Raspberry and Blackberry 

 (Rubus idceus and fruticosus) and the Strawberry (Fray aria elatior, vesta, 

 &c.). The petals of Roses yield the essential oil called Otto or Attar of 

 Roses. Kousso (Bray era cinthelmintica) is used as a vermifuge. Most of 

 the Rosece have astringent bark and roots ; some are unwholesome. San- 

 yuisorbece have astringent properties similar to Rosece. Quittaice contain 

 'in their bark a saponaceous principle, which renders them useful for 

 cleaning silk fabrics. 



CALYCANTHACE^ form a small Order, consisting of shrubs with opposite 

 entire leaves, without stipules ; sepals and petals similar and indefinite ; 



