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 ...
of
epiphytic
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
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, ...
in the tribe
Hylocereeae
The Hylocereeae are a tribe of cacti. Most are found in the tropical forests of Central and northern South America, and are climbers or epiphytes, unlike most cacti. The tribe includes between six and eight genera in different circumscriptio ...
Central America
Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...
, the
Caribbean
The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...
and northern
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
. It should not be confused with ''
Discocactus
''Discocactus'' is a genus of Tropics, tropical cactus, cacti. ''Discocactus'' plants are endemic to southern Brazil, eastern Bolivia, and northern Paraguay. These species are in the risk of extinction in the wild.
Description
The species of th ...
'', which is a different genus.
Species of ''Disocactus'' grow in
tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
regions either on trees as
epiphyte
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
s or on rocks as
lithophyte
Lithophytes are plants that grow in or on rocks. They can be classified as either epilithic (or epipetric) or endolithic; epilithic lithophytes grow on the surfaces of rocks, while endolithic lithophytes grow in the crevices of rocks (and are als ...
s. They have two distinct growth habits. Species such as '' D. phyllanthoides'' have stems which are round at the base but then become flattened and leaflike.
Many of the cultivated plants known as
epiphyllum hybrid
Epiphyllum hybrids, epiphyllums, epicacti, or just epis, also known as orchid cacti, which are widely grown for their flowers, are artificial hybrids derived primarily from species of the genus ''Disocactus''. These ''Disocactus'' species are not ...
s or just epiphyllums are derived from crosses between species of ''Disocactus'' (rather than ''
Epiphyllum
''Epiphyllum'' (; "upon the leaf" in Greek) is a genus of epiphytic plants in the cactus family (Cactaceae), native to Central America and South America. Common names for these species include climbing cacti, orchid cacti and leaf cacti, thoug ...
'') and other genera in the Hylocereeae., p. 286
Description
The species of the genus ''Disocactus'' grow as epiphytes or lithophytes and are shrubby, profusely branched, hanging, up to 3 m long. The shoots are ribbed or flattened, 3-angled or flattened, ribbon-like, 3–10 mm wide, remotely crenate and leaf-like. The main shoot, which rotates near the base, is only flattened at the top, while the side shoots are completely flattened. The thorns on the areoles are bare or with white wool and bristles 4–9 mm long.
The large flowers open during the day, appearing singly or rarely in groups from an areole. They are of different shapes and sizes, 10–15 cm long. The flowers are funnel-shaped or tubular, sometimes zygomorphic and rarely wheel-shaped, receptacular tube curved, embraced by foliaceous scales or 1–few bristles 3–5 mm long. They are bright red, orange, slightly reddish pinkish-orange, light yellow in color, or white. The stamens are often in two rows, with the upper ones sometimes forming a clear throat circle. The sepaloid parts of perianth are 10–30 mm long and 3–7 mm wide, yellow-green; the petaloid parts are 6–8 cm long and 1.5–2 cm wide, orange, reddish at base. The stamens are asymmetrically grouped along the lower side of the throat of the perianth; the style is exserted, 9–13 cm long with 8–9 stigma lobes.
Berry-like ellipsoid fruits are formed that are 7 cm long and 3 cm in diameter, almost bare or covered with a few small scales. They contain broad ovate seeds 1.5 to 2.4 millimeters long and 1 to 1.7 millimeters wide. The seeds are brown-black to almost black and are shiny or, more rarely, somewhat dull.
Taxonomy
''
Pseudorhipsalis
''Pseudorhipsalis'' is genus of cactus, cacti. This genus is often included in ''Disocactus''. It is epiphytic, many branched, and elongated with flattened, serrated cladodes. In its early life, it stands erect, but soon becomes prostrate. It pro ...
'' is sometimes included in ''Disocactus'', but it is kept separate by the International Cactaceae Systematics Group. ''
Aporocactus
''Aporocactus'' is a genus of cacti in the tribe Hylocereeae native to Mexico. It used to be classified as a subgenus in ''Disocactus'', but according to molecular evidence, it should be excluded from ''Disocactus'' and treated as a separate genu ...
'' is formerly included in ''Disocactus'', but it should be a genus on its own according to molecular evidence.
Species
,
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 the following species:
Synonymy
The boundaries of the genera in the tribe Hylocereeae have been subject to considerable change and uncertainty, which is reflected in the number of names which have been used for ''Disocactus'':
*''Bonifazia'' Standl. &
Steyerm.
Julian Alfred Steyermark (January 27, 1909 – October 15, 1988) was a Venezuelan American botanist. His focus was on New World vegetation, and he specialized in the family Rubiaceae.
Life and work
Julian Alfred Steyermark was born in St. Louis ...
Rose
A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...
*''Heliocereus'' (A.Berger) Britton & Rose
*''Lobeira''
Alexander
Alexander () is a male name of Greek origin. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history.
Variants listed here ar ...
Rose
A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...
*''Pseudonopalxochia''
Backeb.
Curt Backeberg (2 August 1894 in Lüneburg, Germany – 14 January 1966) was a German horticulturist especially known for the collection and classification of cacti.
Biography
He travelled extensively through Central and South America, and publi ...