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Binomial nomenclature [ Taxonomy ]

Dictionary of botanic terminology
index of names

     
  In biology the binomial nomenclature  is a standard convention that identifies each species by a scientific name of two words, Latin in form and usually derived from Greek or Latin roots.  
     
The scientific name of a species is formed by the combination of two terms The first name (capitalized) is the genus of the organism, the second (not capitalized) is its species.
For example the scientific name of the Yellow alicoche hedgehog cactus is Echinocereus papillosus, while the Claret-Cup Hedgehog cactus is Echinocereus triglochidiatus.
The first name applies to all species of the genus,  Echinocereus is the name of all hedgehog cactus—but the entire binomial applies only to a single species. Many scientific names describe some characteristic of the organism (as: papillosus = with papillae; triglochidiatus = with three bristles); many are derived from the name of the discoverer or the geographic location of the organism.
Genus and species names are always italicized when printed;  the names of other Taxa (families, etc.) are not. The genus name can be abbreviated to its initial letter (as E. triglochidiatus) when repeated or when several species from the same genus are being listed or discussed in the same paper or report. Subspecies are indicated by a trinomial; The advantages of scientific over common names are that they are accepted by speakers of all languages, that each name applies only to one species, and that each species has only one name.
     
 


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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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