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

 
 
 
Retuse Adjective  [ Botany ]
Adverb: Retusely
Noun: Retuseness

Dictionary of botanic terminology - index of names

 

     
  Of the apex of any laminar structure, e.g., petal, scale, leaf blade, very blunt, slightly notched ending in an obtuse sinus, and divided less than 5% the length of the structure.  
     
[From Latin "retusus", past participle of  "retundere", to beat back : "re-" + "tundere" to beat.]
Retuse leaf tip  [ Botany ]
     
Of a leaf apex rounded or obtuse with a central shallow indentation.
   
 
Retuse (Haworthia)  [ Botany ]
     

The term retuse is also used to categorize a group of flat leaved Haworthias species:
The genus Haworthias is split into various subgenera among them the most popular group are the flat-leaved types, ( Retusae group ). This group includes such plants as H. truncata, H. magnifica, H. pygmaea, H. springbokvlakensis, H. bayeri, H. emelyae and H. retusa.


Haworthia retusa

     

 


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  |