ORDER MONOGYNIA. 



209 



Fig. 108y 



LECTURE XXV. 



CLASS V. PENTANDRIA. 



THE class which we are about to 

 examine, is said to comprehend more 

 than one tenth part of all known spe- 

 cies of plants. It differs from the class 

 Syngenesia in having its jive stamens 

 separate, while the Syngenesious 

 plants have the same number of sta- 

 mens united by means of their an- 

 thers. Plants with five stamens, 

 including those which have anthers 

 united, are said to constitute one fourth 

 part of the vegetable kingdom. 



Order Monogynia. 



There are six orders in the class Pentandria, the first of 

 which, Monogynia, is large and important. Here we find the 

 41st natural order of Linnseus, the AsperifoUa, a name derived 

 from two Latin words, asper, rough, onAjolium, leaf, signifying 

 rough leaved plants. These have monopetalous corollas, with 

 five stamens and five naked seeds. The seeds are dicotyledons ; 

 this natural family is found in the 8th class of Jussieu, and by 

 him is called boraginece, 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 phe- 

 nomenon."* 



The Cynoglossum is perhaps as common as any of the asperi- 

 folice or rough leaved plants. Its common name is hound's 

 tongue, so called from its soft oval leaves, which are thought 

 to resemble the tongue of a dog. Although the Cynoglossum 

 is classed with the rough leaved plants, its leaves are remarka- 

 bly soft, appearing to the touch like velvet ; it is about two feet 

 high, the flowers are of a reddish purple, growing in panicles. f 

 The Lungwort (Pulmonaria), which also belongs to this natural 



* Smith. 



t It is said that the leaves of this plant, if strewed about apartments infested 

 with rats and mice, will expel these vermin. 



Class Pentandria How different from the class Syngenesia Order Mono- 

 gynia Describe the characters of the family Asperifolise Mention the prin- 

 cipal genera in this family. 



18* 



