Discocactus horstii is a charming little cactus described by Buining and Bredero in 1973. The relationship of the genus to other genera is not well understood and is disputed. The relationship of the genus to other genera is not well understood and is disputed.
![]()
About this bookMajor new work on the Cactaceae, published under the auspices of the International Cactaceae Systematics Group (ICSG). An essential purchase for cactaceae specialists and botanical libraries.From the publisher's announcement:Planned as a successor to Backeberg's Cactus Lexicon, The New Cactus Lexicon will be the most scientifically authoritative conspectus of the Cactaceae published for nearly a century.
(Redirected from Mistletoe cactus)
Rhipsalis is a genus of flowering plants in the cactus family, typically known as mistletoe cacti. They are found in parts of Central America, the Caribbean and northern regions of South America. Additionally they inhabit isolated locations in Africa and Asia, and are the only cactus group naturally occurring in the Old World. This is the largest and most widely distributed genus of epiphytic cacti[1] (those which live on other plants without damaging them).
The scientific nameRhipsalis derives from the Ancient Greek term for wickerwork,[2][3] referring to the plants' morphology.
History[edit]
The genus was described by Joseph Gaertner in 1788.[4] But when he described the plant, he had in fact not realised it was a cactus. Instead, he assumed he had found a new species of Cassytha[Note 1], a parasitic laurel from a completely different plant family.
Ecology and distribution[edit]
Rhipsalis is found as pendulous epiphyte in tropical rainforests, some species may also grow epilithic or, rarely, terrestrial.[5][6][7] The genus is found widely in Central America, parts of the Caribbean and a great part of northern and central South America.[8] The center of diversity of Rhipsalis lies in the rainforests of the Mata Atlantica in southeastern Brazil.[6] It is found throughout the New World, and additionally in tropical Africa, Madagascar and Sri Lanka.[9][7] It is the only cactus with a natural occurrence outside the New World.[10]
Rhipsalis pilocarpa fruit
![]() Morphology[edit]
The morphology of Rhipsalis is very variable. The plants can grow mostly pendent, few grow more or less upright or sprawling. There are three main stem shapes: terete, angular and flattened. The stems are succulent, but the degree of succulence varies between the species. Some have very thick stems (e.g. Rhipsalis neves-armondii), whereas other have very thin, filiform stems (e.g. Rhipsalis baccifera, Rhipsalis clavata). In the majority of species, spines are missing or occur only in the juvenile stage (this is most prominent in Rhipsalis dissimilis). Rhipsalis pilocarpa has stems and fruits densely covered by bristes, making this species easily distinguishable from all other Rhipsalis.The flowers are borne lateral or apical and are actinomorphic with a varying number of perianth segments, stamens and carpels. They are small, usually about 1 cm in diameter, white or whitish in most species. Yellowish flowers occur in R. dissimilis and R. elliptica and R. hoelleri is the only Rhipsalis species with red flowers. The fruits are always berries, they are whitish or coloured pink, red or yellow. Vivipary has been observed in R. micrantha and R. baccifera.[11]
Species[edit]
Based on taxonomic treatment in The New Cactus Lexicon[12], 35 species divided into five subgenera (Phyllarthrorhipsalis, Rhipsalis, Epallagogonium, Calamorhipsalis, Erythrorhipsalis) are recognised.
Recent molecular studies[7] showed paraphyly of three subgenera as previously circumscribed (Rhipsalis, Calamorhipsalis and Epallagogonium). So a new subgeneric classification of Rhipsalis with only monophyletic subgenera Rhipsalis, Calamorhipsalis and Erythrorhipsalis is proposed.[1]
Notes[edit]
![]() References[edit]
Literature[edit]
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Rhipsalis&oldid=932282339'
![]() Comments are closed.
|
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
March 2023
Categories |