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

 

 
 
Bract  [ Botany ]
Adjective: Bracteate

Dictionary of botanic terminology - index of names

     
  A bract is a reduced or modified leaf different in various characteristics from the foliage leaves in the axil of which arises a flower or a flower cluster.  
     
Bracts are often found at the base of a flower, (or of a cone) involucral with an inflorescence, they may form a cup around the flower (e.g. Asteraceae) or resemble a normal leaf, or be reduced and scale-like in appearance, or large, brilliantly coloured, similar to petals to emphasize the flowers  (e.g. Poinsetta  Euphorbia pulcherrima). Shoots and flowers may arise from a leaf  axil, but a flower arises more often in the axil of a bract.

 


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  |