''Cleistocactus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the cactus

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Cactaceae,

native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

to mountainous areas - to - of South America (Peru, Uruguay, Bolivia and Argentina). The name comes from the Greek ''kleistos'' meaning closed because the

flowers Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

hardly open.

Description

The plants of the genus are slender stem succulents that are tall, mostly slender and often many-branched up to about 3 m high. They usually form basally branching shrubs, rarely they branch higher and form small trees. The shoots stand upright and then often hang over as they get older; they usually lie down with their ends rising up; more rarely they grow hanging. They usually have many ribs, closely set

areole In botany, areoles are small light- to dark-colored bumps on cactus, cacti out of which grow clusters of Thorns, spines, and prickles, spines. Areoles are important diagnostic features of cactus, cacti, and identify them as a family distinct fr ...

s and

spine Spine or spinal may refer to: Science Biology * Spinal column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoology), ...

s. The areoles on the ribs usually have many fine, hair-like spines with a few firmer spines in between; the spines are rarely longer and coarse. In most species, the flowers appear in large numbers individually from the areoles. The flowers are tubular and the tips hardly open with only the

style Style, or styles may refer to: Film and television * ''Style'' (2001 film), a Hindi film starring Sharman Joshi, Riya Sen, Sahil Khan and Shilpi Mudgal * ''Style'' (2002 film), a Tamil drama film * ''Style'' (2004 film), a Burmese film * '' ...

and

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

usually protruding. In some species (from the earlier genera Borzicereus and Cephalocleistocactus) they appear from conspicuous zones of heavy bristle and hair formation. In adaptation to the pollinators (hummingbirds), the flowers are long, tubular with upright bracts, which are sometimes not or only slightly folded outwards at the tips and thus appear almost closed. They are often slightly

zygomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spir ...

due to an upward bend near the base and/or an oblique flower border (longer or straighter at the top, shorter or more folded at the bottom). The flower colors range from green to white, yellow, orange and red to violet, with shades of red predominating. The densely scaled fruits that emerge after fertilization are relatively small, but usually contain numerous seeds.

Species

Species of the genus ''Cleistocactus'' according to

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

References

* Innes C, Wall B (1995). ''Cacti, Succulents and Bromaliads''. Cassell & The Royal Horticultural Society.

External links

*
photos on www.AIAPS.org
*
photos on www.cactiguide.com
{{Taxonbar, from=Q133967 Cacti of South America Flora of Argentina Flora of Bolivia Flora of Peru Flora of Uruguay Cereeae genera

Description

Species

References

Further reading

External links