Rauhocereus

{{Short description|Genus of plant}} {{Speciesbox |image = Rauhocereus riosaniensis pm.jpg |image_caption = ''Rauhocereus riosaniensis'' in cultivation |status = LC |status_system = IUCN3.1 |status_ref =<ref name="IUCN Red List of Threatened Species 2011 p. ">{{cite journal | title=The IUCN Red List of Threatened Species | journal=IUCN Red List of Threatened Species | date=2011-05-07 | url=https://www.iucnredlist.org/en | access-date=2023-08-19 | page=}}</ref> |display_parents = 3 |genus = Rauhocereus |parent_authority = [[Curt Backeberg|Backeb.]]<ref name=POWO_295613-2/> |species = riosaniensis |authority = Backeb.<ref name=POWO_295613-2/> |synonyms = *''Browningia riosaniensis'' <small>(Backeb.) G.D.Rowley</small> |synonyms_ref = <ref name=POWO_217892-2>{{Cite POWO|title=''Rauhocereus riosaniensis'' Backeb..|id=217892-2|access-date=2023-10-16|mode=cs1}}</ref> }}

'''''Rauhocereus''''' is a [[Monotypic taxon|monotypic]] [[genus]] of [[cactus|cacti]] ([[Family (taxonomy)|family]] Cactaceae). Its only species is '''''Rauhocereus riosaniensis''''',<ref name=POWO_295613-2>{{Cite POWO|title=''Rauhocereus'' Backeb|id=295613-2|access-date=2023-08-19|mode=cs1}}</ref> which has [[night-blooming cereus|nocturnal flowers]].<ref>{{Cite journal |last1=Marcelo-Peña |first1=J. L. |last2=Huamantupa |first2=I. |last3=Särkinen |first3=T. |last4=Tomazello |first4=M. |date=2016 |title=IDENTIFYING CONSERVATION PRIORITY AREAS IN THE MARAÑÓN VALLEY (PERU) BASED ON FLORISTIC INVENTORIES |url=https://journals.rbge.org.uk/ejb/article/view/1597 |journal=Edinburgh Journal of Botany |language=en |volume=73 |issue=1 |pages=95–123 |doi=10.1017/S0960428615000281 |issn=1474-0036|url-access=subscription |doi-access=free }}</ref> It is known from northern [[Peru]] ([[Santa River|Rio Santa]], [[Rio Zana]], [[Chamaya]] and [[Jaén, Peru|Jaén]]).

==Description== The mostly shrubby ''Rauhocereus riosaniensis'', usually branching from the ground, often forms thickets up to 4 meters high. The upright, columnar shoots are bluish-green and have a diameter of {{cvt|8 to 15|cm}}. The 5 to 6 ribs are broken up into many warts. 2 to 8 strong spines, up to {{cvt|5|cm}} long, emerge from the woolly [[areoles]]. The lower ones are initially reddish, the upper ones yellowish. Later all become greyish-white.

The bell-shaped flowers appear near the shoot tip. They open at night, are {{cvt|8 to 10|cm}} long and have a diameter of up to {{cvt|5|cm}}. The flower cup and the flower tube are covered with small scales and curly brown hairs.

The red, fleshy fruits are ovoid with a persistent flower rest. They contain small, ovoid, shiny black seeds.<ref name="Anderson Eggli 2005 p. 558">{{cite book | last1=Anderson | first1=Edward F. | last2=Eggli | first2=Urs | title=Das grosse Kakteen-Lexikon | date=2005 | isbn=3-8001-4573-1 | language=de | page=558| publisher=Ulmer }}</ref>

==Taxonomy== The genus and its only species were first described in 1957 by Curt Backeberg.<ref name=POWO_295613-2/> {{As of|2023|October}}, [[Plants of the World Online]] accepted two subspecies:<ref name=POWO_217892-2/> *''Rauhocereus riosaniensis'' subsp. ''jaenensis'' <small>(Rauh) Ostolaza</small> *''Rauhocereus riosaniensis'' subsp. ''riosaniensis''

=== Hybrids ===

==== × Raustoa ==== {{Main|× Raustoa}} A hybrid of Rauhocereus riosaniensis subsp. Jaenensis and [[Espostoa superba]] is found in [[Jaén province, Peru|Jaén, Peru]]. <ref>{{Cite book |last=Ritter |first=Fredrick |title=Kaktten in Südamerika 4 |year=1981 |pages=1343, 1515 |language=De}}</ref>

==Distribution== ''Rauhocereus riosaniensis'' is found in northern Peru in the Amazonas and Cajamarca regions at altitudes of 500 to 1000 meters.{{citation needed|date=October 2023}}

==References== {{Reflist}}

==External links== *{{Commons category-inline|Rauhocereus|''Rauhocereus''}} *{{Wikispecies-inline|Rauhocereus|''Rauhocereus''}}

[[Category:Cereeae]] [[Category:Cacti of South America]] [[Category:Endemic flora of Peru]] [[Category:Cereeae genera]] [[Category:Monotypic Cactaceae genera]]