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Cyathium (Pl. Cyathia) [ Botany ]

Dictionary of botanic terminology - index of names

Adjective: Cyathiform, Cyathophorous
 
     
  An inflorescence consisting of a cuplike cluster of modified leaves enclosing unisexual flowers or a female flower and several male flowers. Ciathya are the typical inflorescence of the Euphorbia.  
     
From Latin “kuathion”, diminutive of “kuathos” ( a ladle).


A cyathium is the very special pseudanthia (false flower) in the genus Euphorbia (Euphorbiaceae) It is an inflorescence with unisexual flowers (or a female flower and several male flowers) surrounded by a cup-like cluster of involucral bracts. This bracts or bracteoles are usually five (or four). The cyathium comprises also 1 to 10 nectar glands. The true female flower consists of an ovary on a short stem with pistil, it is extremely reduced and stands in the centre. The 5 (-4) male flowers at the base of each bracteole are extremely reduced too, each consist of a single anther on a stem.
The flower-like appearance of the cyathia are often emphasized by brightly coloured nectar glands and by petal-like appendages to the nectar glands, or brightly coloured, petal-like bracts positioned under the cyathia. e.g. the poinsettia.
The cyathia are rarely solitary, but mostly in terminal or axillary cymes or clusters. Male cymes 1–10-flowered.
 
     


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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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