CLASS PENTANDEIA. 



139 



evergreen, with a smooth, grayish bark ; shining, thorny leaves ; 

 whitish flowers ; and scarlet berries : this plant ^s much culti- 



vated in England for fences. 



LECTUEE XXYI. 



PENTANDRIA, FIVE STAMENS. 



183. This class is supposed to compre- 

 hend more than one-tenth part of all 

 known species of plants. It differs from 

 the class Syngenesia in having its five 

 stamens separate. Plants with five sta- 

 mens, including the Syngenesious, or 

 those which have anthers united, are said 

 to constitute one-fourth part of the vege- 

 table kingdom. 



1%4:. .Order Monogynia^ one pistil^ As- 

 'perifolicB^ or Boraginacece. — Here we find 

 a group of plants, called by Linnseus As- 

 'perifolicB (from asper., rough, snidfoUym, 

 leaf), or rough-leaved plants. These have monopetalous corollas, 

 with five stamens and five naked seeds. The seeds are dicoty- 

 ledonous. They now constitute the natural order called JBaragi- 

 nacem^ from the genus Borago. " The change in the corolla of 

 these plants, in general from a bright red to a vivid blue, as the 

 flower expands, apparently caused by the sudden loss of some 

 acid principle, is a very curious phenomenon."* The Cynoglos- 

 snm is an interesting plant for botanical analysis. Its common 

 name, hound's-tongue, is given from its soft, oval leaves. Al- 

 though classed with rough-leaved plants, its pubescence gives 

 to its leaves a softness appearing to the touch like velvet. 

 This plant is about two feet high ; the flowers of a reddish pur- 

 ple, growing in panicles. f The Lungwort {Pulmonarid).^ which 

 also belongs to this natural family, has two species in North 

 America with smooth leaves. The mouse-ear {Myosotls) is* 

 7alued for its medicinal properties ; a species, the a?^'ensis^ or 

 Forget-me-not, is an interesting little blue flower. The grom- 

 well {Lithospermum) is a rough plant with white flowers ; the 

 bark of the plant contains so much silex or flinty matter as to 



* Smith. — This subject we have elsewhere noticed. 



+ It is said that the leaves of this plant, if strewed about apartments infested with rata and mice, 

 will expel these vermin. 



183. Class Pentandria— How different from the class Syngenesia ? — 184. Characteristics of the A» 

 perifolise— Cynoglossum — Lungwort — Myosotis — What other rough-leaved plants are mentioned ia tha 

 first order of the fifth class ? 



