128 THE BOOK OP ROSES. 



SIXTH TRIBE OF SPECIES III. 



Rosa Spinosissima, or Burnet-leafed, 

 Very-thorny Rose. 



SPECIFIC CHARACTERS. 



Shrub, from three to nine feet ; bristly. 



Branches, straight, or nearly straight ; of a green more 

 or less dark ; reddish, or brownish ; more or less 

 covered with feeble thorns, mixed with bristles. 



Thorns, close together, almost equal ; sometimes obli- 

 terated. 



Stipules, usually straight, occasionally sloped ; naked, 

 sometimes enlarged at the extremity, which is 

 fringed with glands and notched. 



Leafstalks, naked, but occasionally hairy or thorny ; 

 glandulous. 



Leaves, composed of from seven to thirteen leaflets ; 

 sometimes of fifteen. 



Leaflets, flat, oval, or orbicular, never lanceolated ; 

 simply, and very rarely doubly toothed ; naked or 

 almost naked on the upper surface, sometimes 

 glaucous or glandulous on the lower. 



Flowers, usually devoid of bracteal leaves, solitary, 

 white, red, or yellowish. 



Flowerstalk, often naked, sometimes hispid and glan- 

 dulous. 



Tube of calyx, globular or oval, usually naked, occa- 

 sionally rather hairy or glandulous. 



Sepals, narrow, single, or slightly divided ; connivent, 

 permanent, naked, or slightly hairy. 



Petals, concave, sometimes emarginated, oboval, or 

 ob-cordiform. 



Disk, very thin, or a little raised ; almost obliterated. 

 Styles, generally hairy and detached. 



