''Schlumbergera kautskyi'' is a species of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family

Cactaceae A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to a small area of the coastal mountains of south-eastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

where its natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

is rocky areas. It is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. It is in the same

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

as the popular

houseplant A houseplant, sometimes known as a pot plant, potted plant, or an indoor plant, is an ornamental plant that is grown indoors. As such, they are found in places like residences and offices, mainly for decorative purposes. Common houseplants are us ...

known as Christmas cactus or Thanksgiving cactus.

Description

''Schlumbergera kautskyi'' resembles other species of the

Schlumbergera ''Schlumbergera'' is a small genus of cacti with six to nine species found in the coastal mountains of south-eastern Brazil. These plants grow on trees or rocks in habitats that are generally shady with high humidity, and can be quite differen ...

'' in that it has leafless green stems which act as

photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

organs. The stems (

cladode Phylloclades and cladodes are flattened, photosynthetic shoots, which are usually considered to be modified branches. The two terms are used either differently or interchangeably by different authors. ''Phyllocladus'', a genus of conifer, is name ...

s) are composed of strongly flattened segments, which have "teeth" of varying shapes along their edges and at the ends, which are "cut off" (truncated) rather than pointed. Individual segments, which are very variable, are usually long by wide (although lengths of up to and widths up to are known). Special structures characteristic of cacti, called "

areole 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 - W ...

s", occur at the end of the segments. The areoles, which have brown wool and short bristles, are where the flower buds appear. The flowers are usually held slightly above the horizontal with the higher side different from the lower side (

zygomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

, specifically bilaterally symmetrical). They are purple in colour, about long by across. When ripe, the four-angled fruit is yellow-green with red tones, about long by wide, and contains about 150 dark brown or black seeds, each about with a diameter of about .

Taxonomy

''S. kautskyi'' was the last species of the genus ''Schlumbergera'' to be given a scientific name. In 1991, Horobin and McMillan described it as a subspecies of ''S. truncata'', ''S. truncata'' ssp. ''kautsky''; in the same year N.P. Taylor raised it to a full species. The specific epithet relates to the collector whose surname was Kautsky. A 2011

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study confirmed its status as a full species within the genus.

Distribution and habitat

''S. kautskyi'' occurs only in a small area, estimated in 2002 to be less than , of the coastal mountains of south-east

, in the state of

Espírito Santo Espírito Santo (, , ; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attra ...

, located in the southernmost part of the tropics. Sites where it has been found include Pico da Pedra Azul. Plants grow at altitudes of . Because of their height and proximity to the Atlantic Ocean, the coastal mountains produce high altitude moist forests – warm moist air is forced upwards into higher, colder locations where it condenses. ''Schlumbergera kautskyi'' grows either on rocks (

epilithic 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 also ...

) or more rarely on trees (

epiphytic An epiphyte is an organism that grows on the surface of a 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 epiphytes grow are called phoroph ...

). It is listed as "endangered" in the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

in view of the limited area in which it occurs and the threat of residential development.

References

External links

Photograph of ''S. kautskyi''
{{Taxonbar, from=Q281707 Flora of Brazil kautskyi Endangered plants Plants described in 1991 Taxonomy articles created by Polbot