Cleistocactus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of columnar cacti

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

 from Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

, Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

 and Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. The name comes from the Greek kleistos meaning closed because the flowers hardly open.

The stems are tall and mostly slender and often many branched with numerous ribs with closely set areole

Areole

Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...

s and spine

Thorns, spines, and prickles

In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...

s. The flowers are tubular and the tips hardly open with only the style and stamens usually protruding.

Synonymy

The following genera have been brought into synonymy with this genus:

• Akersia Buining
• Bolivicereus Cárdenas
  Cárdenas
  Cárdenas is a surname generally of Spanish origin.FAMILY ORIGIN:The family name Cardenas is a local surname which came from the region of La Rioja, Spain...
  
  
• Borzicactella H.Johnson ex F.Ritter
• Borzicactus Riccob
• Borzicereus Fric
  Alberto Vojtech Fric
  Alberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
  
   & Kreuz. (orth. var.)
• Cephalocleistocactus F.Ritter
• Cleistocereus Fric
  Alberto Vojtech Fric
  Alberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
  
   & Kreuz. (orth. var.)
• Clistanthocereus Backeb.
• Demnosa Fric
  Alberto Vojtech Fric
  Alberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
  
  
• Gymnanthocereus Backeb.
• Hildewintera F.Ritter
• Loxanthocereus Backeb.
• Maritimocereus Akers
• Pseudoechinocereus Buining (nom. inval.)
• Seticereus Backeb.
• Seticleistocactus Backeb.
• Winteria F.Ritter
• Winterocereus Backeb.

External links

photos on www.AIAPS.org photos on www.cactiguide.com