''Haworthiopsis'' is a

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 ...

succulent plant In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

s in the subfamily

Asphodeloideae Asphodeloideae is a subfamily of the monocot family Asphodelaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae ''sensu stricto''. The family Asphodelaceae has now been proposed to be a nomen conserv ...

. The genus was previously included in ''

Haworthia ''Haworthia'' is a large genus of small succulent plants endemic to Southern Africa (Mozambique, Namibia, Lesotho, Eswatini and South Africa). Like the aloes, they are members of the subfamily Asphodeloideae and they generally resemble mi ...

''. Species in the genus are typically short

perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

s, with leaves often arranged in a rosette and frequently having raised white markings. The two-lipped flowers are borne on a tall stalk and are small – less than long – and pale in colour. Many species are cultivated as house plants or by succulent enthusiasts.

Description

''Haworthiopsis'' species are short perennial plants, with or without an obvious stem. The leaves either form a rosette or are arranged in various spirals on a more extended stem.Molteno S. (2022), "Phyllotaxis in Asphodelaceae subfam. Alooideae: a tool in taxon delimitation." ''Haseltonia'' 28(1), https://doi.org/10.2985/026.028.0107 Individual leaves are smooth or have white markings, which may take the form of small protuberances (tubercules) or be more pointed, almost spine-like. The white markings may be on the lower surface of the leaf only, or on both surfaces, and may also extend to the leaf margins. The upper leaf surfaces are "windowed" in some species, and the margins may have toughened teeth. The flowers are borne in a

raceme A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...

on a long, stiff stalk ( peduncle) which also bears a few bracts without flowers in their junctions with the stalk. Each flower is less than long, with white to green, pink or brown

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s, forming a two-lipped (bilabiate) structure with a hexagonal or rounded hexagonal base. Both the outer and inner tepals are joined together at their bases. The

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s and the

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

are enclosed within the tepals. The fruit is a narrowly ovoid capsule with black or dark brown seeds. Two-lipped flowers were considered a distinguishing characteristic of the genus ''

'', before ''Haworthiopsis'' and ''

Tulista ''Tulista'' is a small genus of succulent plants endemic to South Africa. They were formerly included within the genus ''Haworthia''. Characteristics The genus is characterised by a large size (relative to other haworthias), by their stemless ro ...

'' were split off. More detailed features of the flowers now identify the three genera. In ''Haworthiopsis'', the flowers and their styles are usually straight rather than curved; the outer and inner whorls of three tepals are joined to one another at the base; and the flowers taper smoothly into the flower stem (

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

) rather than being broader at the base with a sharp junction.

Taxonomy

The genus ''Haworthiopsis'' was erected by Gordon Rowley in 2013, with the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

Haworthiopsis coarctata ''Haworthiopsis coarctata'', formerly ''Haworthia coarctata'', is a species of flowering succulent plant from the Eastern Cape Province, South Africa and naturalized in Mexico. It is one of the species of '' Haworthiopsis'' that is commonly culti ...

''. The ending ''-opsis'' derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

(opsis), meaning 'appearance', hence ''Haworthiopsis'' means "like ''Haworthia''". The taxonomic history of the genus is complex. In 1753,

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

followed authors before him in using the genus ''

Aloe ''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Accessed on: 06 Nov 2022 The most wid ...

'' for a wide range of plants now placed in the tribe

Aloeae Aloeae is a tribe of succulent plants in the subfamily Asphodeloideae of the family Asphodelaceae, consisting of the aloes and their close relatives. The taxon may also be treated as the subfamily Alooideae by those botanists who retain the nar ...

by those using the broad

circumscription Circumscription may refer to: *Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) *Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of the family

Asphodelaceae Asphodelaceae is a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription has varied widely. In its current circumscription in the APG IV system, it includes about 40 ...

(''sensu'' APG III onwards). Linnaeus's ''Aloe'' species included two now placed in ''Haworthiopsis''. The genus ''

'' was established by Henri Auguste Duval in 1809 for former ''Aloe'' species with smaller whitish two-lipped (bilabiate) flowers. Many additional taxa were later added, at both species and infraspecies ranks. This has been described as "causing a great deal of confusion". In 1971, M.B. Bayer divided ''Haworthia'' into three subgenera: ''H.'' subg. ''Haworthia'', ''H.'' subg. ''Hexangulares'' and ''H.'' subg. ''Robustipedunculatae''.

Phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

studies, particularly from 2010 onwards, showed that ''Haworthia'' and other genera related to ''Aloe'' were not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

. Accordingly, in 2013, Rowley separated most of the species formerly placed in ''Haworthia'' subg. ''Hexangulares'' into a new genus, ''Haworthiopsis''. ''Haworthiopsis'' was revised in 2013 by Manning et al. so that the genus more closely correlated with the former subgenus, a revision described as "more coherent" by Gildenhuys and Klopper in 2016.

Sections and Species

In 2016, Gildenhuys and Klopper proposed a division of the genus into seven sections, although noting that it could need re-evaluation when further phylogenetic studies had been carried out. Their section ''Koelmaniorum'' is least clearly placed in the genus, and the status of sections ''Limifoliae'' and ''Tessellatae'' is also uncertain. , the

World Checklist of Selected Plant Families The World Checklist of Selected Plant Families (usually abbreviated to WCSP) is an "international collaborative programme that provides the latest peer reviewed and published opinions on the accepted scientific names and synonyms of selected plan ...

accepted the following species:

References

{{Taxonbar, from=Q39152298 Asphodelaceae genera