Cleistocactus

Cleistocactus is a genus of flowering plants in the cactus family Cactaceae, native to mountainous areas - to - of South America (Peru, Uruguay, Bolivia and Argentina). The name comes from the Greek kleistos meaning closed because the flowers 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 areoles and spines. 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 and stamens 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 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 since October 2025Template:Dated maintenance category (articles):

Image	Scientific name	Distribution
	Cleistocactus aurantiacus M.Lowry	Bolivia
File:Cleistocactus baumannii (9215676698).jpg	Cleistocactus baumannii (Lem.) Lem.	Argentina, Paraguay, Bolivia, Uruguay
File:Cleistocactus brookeae1PAKAL.jpg	Cleistocactus brookeae Cárdenas	Bolivia
File:Cleistocactus buchtienii 2.jpg	Cleistocactus buchtienii Backeb.	Bolivia
File:Cleistocactus candelilla 2.jpg	Cleistocactus candelilla Cárdenas	Bolivia
	Cleistocactus capadalensis F.Ritter	Bolivia (Chuquisaca)
File:Cleistocactus colademononis (4974876280).jpg	Cleistocactus colademononis (Diers & Krahn) Mottram	Bolivia
File:Cleistocactus micropetalus pm.jpg	Cleistocactus crassicaulis Cárdenas	Bolivia
File:Cleistocactus dependens 3.jpg	Cleistocactus dependens Cárdenas	Bolivia
File:Cleistocactus glaucus.jpeg	Cleistocactus glaucus F.Ritter	Bolivia
File:Cleistoc hildegardiae.jpg	Cleistocactus hildegardiae F.Ritter	Bolivia
File:Cleistocactus hyalacanthus pm1.jpg	Cleistocactus hyalacanthus (K.Schum.) Rol.-Goss.	Argentina, Bolivia
File:IMG 8257-1-Cleistocactus laniceps.jpg	Cleistocactus laniceps (K.Schum.) Rol.-Goss.	Bolivia
File:Cleistocactus luribayensis 2.jpeg	Cleistocactus luribayensis Cárdenas	Bolivia
File:Cleistocactus morawetzianus - Botanischer Garten, Dresden, Germany - DSC08890.JPG	Cleistocactus morawetzianus Backeb.	Peru
File:Cleistocactus orthogonus 5.jpg	Cleistocactus orthogonus Cárdenas	Bolivia
File:Cleistocactus parviflorus-IMG 6945.jpg	Cleistocactus parviflorus (K.Schum.) Rol.-Goss.	Bolivia
File:Cleistocactus pungens 8.jpg	Cleistocactus pungens F.Ritter	Peru
File:Cleistocactus ritteri, Jardín Botánico de Múnich, Alemania, 2013-05-04, DD 01.jpg	Cleistocactus ritteri Backeb.	Bolivia
File:Cleistocactus samaipatanus 001.JPG	Cleistocactus samaipatanus (Cárdenas) D.R.Hunt	Bolivia, Brazil
File:Cleistocactus smaragdiflorus kz2.JPG	Cleistocactus smaragdiflorus (F.A.C.Weber) Britton & Rose	Argentina, Bolivia
File:Cleistocactus strausii (3424130733).jpg	Cleistocactus strausii (Heese) Backeb.	Bolivia
File:Cleistocactus tominensis - Botanischer Garten, Dresden, Germany - DSC08891.JPG	Cleistocactus tominensis (Weing.) Backeb.	Bolivia
File:Cleistocactus variispinus3.png	Cleistocactus variispinus F.Ritter	Bolivia
File:Cleistocactus palhuayensis pm1.jpg	Cleistocactus viridiflorus Backeb.	Bolivia (La Paz)
File:Cactus Flower (Cleistocactus winteri).jpg	Cleistocactus winteri D.R.Hunt	Bolivia

References

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

Further reading

• Cactiguide.com, which is in turn referenced from several books which are listed on that site. The principal book listed here is The Cactus Family by Edward F. Anderson.

External links

• Template:In lang photos on www.AIAPS.org
• Template:In lang photos on www.cactiguide.com