''Rauhocereus'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

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 ...

cacti A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

(

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). Its only species is ''Rauhocereus riosaniensis'', which has nocturnal flowers. It is known from northern

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

( Rio Santa, Rio Zana, Chamaya and

Jaén Jaén may refer to: Places Peru *Jaén Province, Peru, a province in Cajamarca Region, Peru ** Jaén District, one of twelve districts of the province Jaén in Peru ***Jaén, Peru, a city in Peru, capital of the Jaén Province Philippines * Jaen ...

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 . The 5 to 6 ribs are broken up into many warts. 2 to 8 strong spines, up to long, emerge from the woolly

areoles In botany, areoles are small light- to dark-colored bumps on cacti out of which grow clusters of spines. Areoles are important diagnostic features of cacti, and identify them as a family distinct from other succulent plants. Gordon Rowley - Wh ...

. 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 long and have a diameter of up to . 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.

Taxonomy

The genus and its only species were first described in 1957 by Curt Backeberg. ,

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 ...

accepted two subspecies: *''Rauhocereus riosaniensis'' subsp. ''jaenensis'' (Rauh) Ostolaza *''Rauhocereus riosaniensis'' subsp. ''riosaniensis''

Distribution

''Rauhocereus riosaniensis'' is found in northern Peru in the Amazonas and Cajamarca regions at altitudes of 500 to 1000 meters.

References

External links

* * {{Taxonbar, from1=Q8182275, from2=Q148553 Cereeae Cacti of South America Endemic flora of Peru Cereeae genera Monotypic Cactaceae genera