Haworthiopsis

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Monocots
Ordo: Asparagales

Familia: Asphodelaceae
Subfamilia: Asphodeloideae
Genus: Haworthiopsis
Overview of species

H. attenuata – H. bruynsii – H. coarctata – H. fasciata – H. glauca – H. granulata – H. koelmaniorum – H. limifolia – H. longiana – H. nigra – H. pungens – H. reinwardtii – H. scabra – H. sordida – H. tessellata – H. venosa – H. viscosa – H. woolleyi

Nothospecies: (2)
H. × rigida – H. × tauteae
Name

Haworthiopsis G.D.Rowley, Alsterworthia Int., Special Issue 10: 4 (2013)

Type species: Haworthiopsis coarctata (Haw.) G.D.Rowley, Alsterworthia Int., Special Issue 10: 4 (2013)

Synonyms

Homotypic
Haworthia sect. Hexangulares Uitewaal, Succulenta (Amsterdam) 5: 51. (1947)
Heterotypic
Aloe sect. Parviflorae Haw., Trans. Linn. Soc. London 7: 6. (1804)
Haworthia sect. Trifariae Haw., Saxifrag. enum. 2: 49. (1821)
Haworthia sect. Luridae Haw., Saxifrag. enum. 2: 50. (1821)
Aloe sect. Luridae (Haw.) Salm-Dyck, Aloes Mesembr. 1: sect. 7. (1836)
Aloe subgen. Parviflorae (Haw.) Salm- Dyck, Aloes Mesembr. 1.: Tabula synoptica Sectionum. (1836)
Aloe sect. Tessellatae Salm-Dyck, Aloes Mesembr. 1: sect. 8. (1836)
Aloe sect. Tortuosae Salm-Dyck, Aloes Mesembr. 1: sect. 4. (1836)
Aloe sect. Triquetrae Salm-Dyck, Aloes Mesembr. 1: sect. 3. (1836)

Distribution
Native distribution areas:

Africa
South Tropical Africa
Mozambique.
Southern Africa
Cape Provinces, Namibia, KwaZulu-Natal, Free State, Swaziland, Northern Provinces.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Rowley, G.D. 2013. Generic concepts in the Alooideae, Part 4 Haworthiopsis and Tulista: old wine in new bottles. Alsterworthia International. The Succulent Asphodelaceae Journal, Special Issue 10: 4.

Additional references

Gildenhuys, S.D. & Klopper, R.R. 2016. A synoptic review and new infrageneric classification for the genus Haworthiopsis (Xanthorrhoeaceae: Asphodeloideae). Phytotaxa 265(1): 1–26. DOI: 10.11646/phytotaxa.265.1.1
Manning, J.C. Boatwright, J.S., Daru, B.H., Maurin, O. & van der Bank, M. 2014. A molecular phylogeny and generic classification of Asphodelaceae subfamily Alooideae: a final resolution of the prickly issue of polyphyly in the alooids? Systematic Botany 39(1): 55–74. DOI: 10.1600/036364414X678044 ResearchGate Reference page.

Links

Govaerts, R. et al. 2019. Haworthiopsis in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2019 March 5. Reference page.
International Plant Names Index. 2019. Haworthiopsis. Published online. Accessed: 5 March 2019.
Tropicos.org 2019. Haworthiopsis. Missouri Botanical Garden. Published online. Accessed: 5 March 2019.

Vernacular names

Haworthiopsis is a genus of succulent plants in the subfamily Asphodeloideae. The genus was previously included in Haworthia. Species in the genus are typically short perennial plants, 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 17 mm (0.7 in) 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.[2] 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.[3][4]

The flowers are borne in a raceme 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 17 mm (0.7 in) long, with white to green, pink or brown tepals, 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 stamens and the style are enclosed within the tepals. The fruit is a narrowly ovoid capsule with black or dark brown seeds.[3][4]

Two-lipped flowers were considered a distinguishing characteristic of the genus Haworthia, before Haworthiopsis and Tulista 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) rather than being broader at the base with a sharp junction.[3]
Taxonomy

The genus Haworthiopsis was erected by Gordon Rowley in 2013,[1] with the type species Haworthiopsis coarctata.[3] The ending -opsis derives from the Greek ὀψις (opsis), meaning 'appearance',[5] hence Haworthiopsis means "like Haworthia".

The taxonomic history of the genus is complex. In 1753, Carl Linnaeus followed authors before him in using the genus Aloe for a wide range of plants now placed in the tribe Aloeae by those using the broad circumscription of the family Asphodelaceae (sensu APG III onwards). Linnaeus's Aloe species included two now placed in Haworthiopsis. The genus Haworthia 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".[4] In 1971, M.B. Bayer divided Haworthia into three subgenera: H. subg. Haworthia, H. subg. Hexangulares and H. subg. Robustipedunculatae.[6]

Phylogenetic studies, particularly from 2010 onwards, showed that Haworthia and other genera related to Aloe were not monophyletic.[7][8] Accordingly, in 2013, Rowley separated most of the species formerly placed in Haworthia subg. Hexangulares into a new genus, Haworthiopsis.[9] Haworthiopsis was revised in 2013 by Manning et al. so that the genus more closely correlated with the former subgenus,[3] a revision described as "more coherent" by Gildenhuys and Klopper in 2016.[4]
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.[4]

As of October 2017, the World Checklist of Selected Plant Families accepted the following species:[10]

Section	Image	Scientific name	Description	Distribution
Attenuatae		Haworthiopsis attenuata (Haw.) G.D.Rowley		South Africa (southern Cape Provinces)
Haworthiopsis		Haworthiopsis coarctata (Haw.) G.D.Rowley	small, smooth, rounded tubercles	South Africa (southern Cape Provinces)
		Haworthiopsis fasciata (Willd.) G.D.Rowley	has a light color, and fibrous leaves with glabrous inner surfaces	South Africa (southern Cape Provinces)
		Haworthiopsis glauca (Baker) G.D.Rowley	has a blue ("glaucous") colour	South Africa (southern Cape Provinces)
		Haworthiopsis longiana (Poelln.) G.D.Rowley	has long, thin, elongated leaves	South Africa (southern Cape Provinces)
		Haworthiopsis reinwardtii (Salm-Dyck) G.D.Rowley	has larger, flatter, whiter tubercles, and is often more slender than H. coarctata	South Africa (southern Cape Provinces)
Limifoliae		Haworthiopsis limifolia (Marloth) G.D.Rowley	has splayed leaves usually with raised lateral lines or wrinkles on the leaf surfaces	Eswatini, southern Mozambique, South Africa (KwaZulu-Natal, Northern Provinces)
Koelmaniorum		Haworthiopsis koelmaniorum (Oberm. & D.S.Hardy) Boatwr. & J.C.Manning	has scabrid, dark brown opaque leaves	South Africa (Mpumalanga)
Tessellatae		Haworthiopsis granulata (Marloth) G.D.Rowley		South Africa (Cape Provinces)
		Haworthiopsis tessellata (Haw.) G.D.Rowley		Namibia, South Africa (Cape Provinces, Free State, Northern Provinces)
		Haworthiopsis venosa (Lam.) G.D.Rowley	has visible veins on its upper leaf surfaces	South Africa (south-western Cape Provinces)
		Haworthiopsis woolleyi (Poelln.) G.D.Rowley		South Africa (southern Cape Provinces)
Trifariae		Haworthiopsis nigra (Haw.) G.D.Rowley	has a dark colour and concolorous tubercles	South Africa (southern Cape Provinces)
		Haworthiopsis pungens (M.B.Bayer) Boatwr. & J.C.Manning	has hard, sharp ("pungent") leaf tips	South Africa (southern Cape Provinces)
		Haworthiopsis scabra (Haw.) G.D.Rowley	a stemless species with a rough scabrid leaf surface	South Africa (south-western and south-south-western Cape Provinces)
		Haworthiopsis viscosa (L.) Gildenh. & Klopper	has a lighter brown mat surface, and no tubercles	South Africa (Cape Provinces)
Virescentes		Haworthiopsis bruynsii (M.B.Bayer) G.D.Rowley	Has evolved a retuse shape, but is nonetheless a member of the genus.	South Africa (southern Cape Provinces)
		Haworthiopsis sordida (Haw.) G.D.Rowley	has dark, dusty ("sordid") leaves with rounded tips	South Africa (southern Cape Provinces)

References

"Haworthioposis", World Checklist of Selected Plant Families, Royal Botanic Gardens, Kew, retrieved 2017-10-16
Molteno S. (2022), "Phyllotaxis in Asphodelaceae subfam. Alooideae: a tool in taxon delimitation." Haseltonia 28(1), https://doi.org/10.2985/026.028.0107
Manning, John; Boatwright, James S.; Daru, Barnabas H.; Maurin, Olivier & Bank, Michelle van der (2014), "A Molecular Phylogeny and Generic Classification of Asphodelaceae Subfamily Alooideae: A Final Resolution of the Prickly Issue of Polyphyly in the Alooids?", Systematic Botany, 39 (1): 55–74, doi:10.1600/036364414X678044
Gildenhuys, Sean D. & Klopper, Ronell R. (2016), "A synoptic review and new infrageneric classification for the genus Haworthiopsis (Xanthorrhoeaceae: Asphodeloideae)" (PDF), Phytotaxa, 265 (1): 1–26, doi:10.11646/phytotaxa.265.1.1, hdl:2263/57046, retrieved 2017-10-18
Stearn, W.T. (2004), Botanical Latin (4th (p/b) ed.), Portland, Oregon: Timber Press, p. 257, ISBN 978-0-7153-1643-6
Bayer, M.B. (1971), "Changes in the genus Haworthia", Cactus and Succulent Journal (US), 43: 157–162, retrieved 2017-10-18
Klopper, R.R.; Van Wyk, A.E. & Smith, G.F. (2010), "Phylogenetic relationships in the family Asphodelaceae (Asparagales)", Biodiversity and Ecology/Schumannia, 3: 9–36, retrieved 2017-10-18
Daru, B.H.; Manning, J.C.; Boatwright, J.S.; Maurin, O.M.; Maclean, N.; Kuzmina, M. & van der Bank, M. (2013), "Molecular and morphological analysis of subfamily Alooideae (Asphodelaceae) and the inclusion of Chortolirion A. Berger in Aloe L.", Taxon, 62 (1): 62–76, doi:10.1002/tax.621006, hdl:10566/3363, JSTOR 24389313
Rowley, G.D. (2013), "Generic concepts in the Alooideae 3: The phylogenetic story", Alsterworthia International, 10: 1–7; cited in Gildenhuys & Klopper (2016)
"Search for Haworthiopsis", World Checklist of Selected Plant Families, Royal Botanic Gardens, Kew, retrieved 2017-10-16