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(1) Pinnate (compound leaf) [ Botany ]
Synonym: Pectinate
Adverb: Pinnately

Dictionary of botanic terminology
index of names

     
  Of a  featherlike compound leaf that is divided up into many small leaflets.  
     


Imparipinnate
(odd pinnate)


Paripinnate
(even pinnate)

Of a  featherlike compound leaf that is divided up into many small leaflets, arranged in rows along either side of an axis (midrib) called a rachis  (pectinate) Each leaflet is known as a pinna, and where the pinnae are themselves divided, the secondary divisions are known as pinnules.

Imparipinnate (odd pinnate): A pinnate leaf with a single terminal leaflet, and therefore usually with an odd number of leaflets.
Paripinnate (even pinnate): A pinnately compound leaf without a single terminal leaflet, and therefore usually with an even number of leaflets.

     
(2) Pinnate (leaf vein)  [ Botany ]
Adverb: Pinnately
     
  Of veins, with the secondary veins (veinlet) arranged regularly (compare with penniveined)  
     

 


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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
     

 

 

 

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