| Home | E-mail | Cactuspedia | Mail Sale Catalogue | Links | Information | Search  |

 
 
 
Compound leaf  [ Botany ]

Dictionary of botanic terminology - index of names

     
  A compound leaf is a leaf that is divided into two or multiple separate blade segment called leaflets or pinnae.  
     
compound leaf The leaf segments are more or less similar and are attached to the rachis (midrib or axis) by a petiolule.

The whole leaf is attached to the stem at a node by a petiole. All the leaflets of a compound leaf are oriented in the same plane. When a compound leaf falls, it falls as a unit.

A double compound (bipinnate) leaf is one in which each leaflet of a compound leaf is also made up of secondary leaflets.

           

;
 

 

 


Advertising



 

 

1


 
 
 
 
Holdfast roots  [ Botany  ]

Dictionary of botanic terminology - index of names

 
     
  Some species of climbing plants develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place.  
     
Climbing plants, like the poison ivy (Toxicodendron radicans), Boston ivy (Parthenocissus tricuspidata), and trumpet creeper (Campsis radicans),  develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place. Usually the Holdfast roots die at the end of the first season, but in some species they are perennial. In the tropics some of the large climbing plants have hold-fast roots by which they attach themselves, and long, cord-like roots that extend downward through the air and may lengthen and branch for several years until they strike the soil and become absorbent roots.

Major references and further lectures:
1) E. N. Transeau “General Botany” Discovery Publishing House, 1994
   

 

 

 

| Home | E-mail | Cactuspedia | Mail Sale Catalogue | Links | Information | Search  |