Rosacem 165 



berry ; cynarrhodum. Rose ; follicles. Meadow-sweet ; ox pome, 

 Apple.) 



This large and important order is widely distributed, espe- 

 cially in the temperate regions. Many of the plants very much 

 resemble those of the Ranunculaceae, but a careful examination 

 will show the great distinction from that order in the perigynous 

 stamens and petals. 



The Rosacese are divided into four sub-orders : — 



1. Drupace/E or Amygdale^e. Trees or shrubs with 

 simple leaves ; fruit a drupe. Many parts of the plants con- 

 tain hydrocyanic or prussic acid. 



Prunus is the only British genus of this sub-order. It has 

 the nut of the drupe smooth or slightly seamed. The native 

 species include the Sloe, Wild Plum, and Cherry. Amongst 

 exotic species of the same genus which are largely cultivated 

 are the Apricot, Cherry Laurel, and Portuguese Laurel. 



Amygdalus is the exotic genus which yields us Almonds, 

 both bitter and sweet. Peaches, and Nectarines. 



2. RosejE. Shrubs or herbs ; stipules adherent ; ovaries 

 one or more, not adherent to calyx ; fruit etserio or follicles. 



Principal British Plants. 



Agrimonia, Agrimony. Flowers in loose spikes ; calyx 

 five-cleft, top-shaped, with hooked bristles ; stamens not more 

 than fifteen ; carpels two. The plant was formerly used by 

 herbalists. 



Fragaria, Strawberry. Calyx ten-cleft, in two rows ; fruit 

 an etaerio of achenes on an enlarged and fleshy receptacle. 



Potentilla differs from the Strawberry principally in the fruit 

 being on a dry receptacle ; P. Torfnentilla has but four petals. 



Posa. Calyx urn-shaped ; fruit a cynarrhodum. There are 

 several species of wild Roses and Briars, from which many 

 of our cultivated Roses are obtained ; others come from exotic 

 species. 



Rubus, Bramble. Calyx five-cleft ; fruit etserio of drupes. 

 The genus includes the Raspberry, Blackberry, Dewberrjf, and 

 Cloudberry. 



