Haworthiopsis

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Haworthiopsis
Ab plant 846.jpg
Haworthiopsis attenuata
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Asphodelaceae
Subfamily: Asphodeloideae
Tribe: Aloeae
Genus: Haworthiopsis
G.D.Rowley [1]
Type species
Haworthiopsis coarctata

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.

Contents

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]

Haworthiopsis sp.jpg
Haworthiopsis sp. with peduncle and raceme
Haworthiopsis inflorescence.jpg
Detail of raceme
Haworthiopsis inflorescence2.jpg
Raceme opening with flower
Haworthiopsis flower.jpg
Flower detail

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]

SectionImageScientific nameDescriptionDistribution
Attenuatae Haworthia no Jardim Botanico do Recife.jpg Haworthiopsis attenuata (Haw.) G.D.RowleySouth Africa (southern Cape Provinces)
Haworthiopsis Haworthia coarctata yc.jpg Haworthiopsis coarctata (Haw.) G.D.Rowleysmall, smooth, rounded tuberclesSouth Africa (southern Cape Provinces)
Haworthia fasciata - hankey 2.jpg Haworthiopsis fasciata (Willd.) G.D.Rowleyhas a light color, and fibrous leaves with glabrous inner surfacesSouth Africa (southern Cape Provinces)
Haworthia glauca var jonesii jonesiae 2.jpg Haworthiopsis glauca (Baker) G.D.Rowleyhas a blue ("glaucous") colourSouth Africa (southern Cape Provinces)
Haworthiopsis longiana in cultivation 5.jpg Haworthiopsis longiana (Poelln.) G.D.Rowleyhas long, thin, elongated leavesSouth Africa (southern Cape Provinces)
HaworthiaReinwardtii.jpg Haworthiopsis reinwardtii (Salm-Dyck) G.D.Rowleyhas larger, flatter, whiter tubercles, and is often more slender than H. coarctataSouth Africa (southern Cape Provinces)
Limifoliae Haworthiopsis limifolia var. limifolia f. spiralis.jpg Haworthiopsis limifolia (Marloth) G.D.Rowleyhas splayed leaves usually with raised lateral lines or wrinkles on the leaf surfaces Eswatini, southern Mozambique, South Africa (KwaZulu-Natal, Northern Provinces)
Koelmaniorum Haworthia koelmaniorum mcmrurtyii.jpg Haworthiopsis koelmaniorum (Oberm. & D.S.Hardy) Boatwr. & J.C.Manninghas scabrid, dark brown opaque leavesSouth Africa (Mpumalanga)
Tessellatae Haworthia venosa granulata - MBB.jpg Haworthiopsis granulata (Marloth) G.D.RowleySouth Africa (Cape Provinces)
Haworthia tessellata (5260919162).jpg Haworthiopsis tessellata (Haw.) G.D.Rowley Namibia, South Africa (Cape Provinces, Free State, Northern Provinces)
Haworthia venosa MBB Felix unite 2.jpg Haworthiopsis venosa (Lam.) G.D.Rowleyhas visible veins on its upper leaf surfacesSouth Africa (south-western Cape Provinces)
Haworthiopsis woolleyi (Poelln.) G.D.RowleySouth Africa (southern Cape Provinces)
Trifariae Haworthia nigra - leaf detail 8.jpg Haworthiopsis nigra (Haw.) G.D.Rowleyhas a dark colour and concolorous tuberclesSouth Africa (southern Cape Provinces)
Haworthia pungens - Braamrivier South Africa.jpg Haworthiopsis pungens (M.B.Bayer) Boatwr. & J.C.Manninghas hard, sharp ("pungent") leaf tipsSouth Africa (southern Cape Provinces)
2 Haworthia scabra var starkiana in cultivation.jpg Haworthiopsis scabra (Haw.) G.D.Rowleya stemless species with a rough scabrid leaf surfaceSouth Africa (south-western and south-south-western Cape Provinces)
Haworthia viscosa 1.jpg Haworthiopsis viscosa (L.) Gildenh. & Klopperhas a lighter brown mat surface, and no tuberclesSouth Africa (Cape Provinces)
Virescentes Haworthia bruynsii - haworthiopsis.jpg Haworthiopsis bruynsii (M.B.Bayer) G.D.RowleyHas evolved a retuse shape, but is nonetheless a member of the genus.South Africa (southern Cape Provinces)
Haworthia sordida - RSA 4.jpg Haworthiopsis sordida (Haw.) G.D.Rowleyhas dark, dusty ("sordid") leaves with rounded tipsSouth Africa (southern Cape Provinces)

Related Research Articles

<i>Aloe</i> Genus of succulent flowering plants

Aloe is a genus containing over 650 species of flowering succulent plants. The most widely known species is Aloe vera, or "true aloe". It is called this because it is cultivated as the standard source for assorted pharmaceutical purposes. Other species, such as Aloe ferox, are also cultivated or harvested from the wild for similar applications.

<span class="mw-page-title-main">Asphodeloideae</span> Subfamily of flowering plants, in monocot family Asphodelaceae

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 conservandum, and the proposal has been recommended for ratification in 2017. In that case, Asphodelaceae will have priority over Xanthorrhoeaceae. This is reflected in the APG IV family lists.

<span class="mw-page-title-main">Asphodelaceae</span> Family of flowering plants in the order Asparagales

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 genera and 900 known species. The type genus is Asphodelus.

<i>Aristaloe</i> Monotypic genus of flowering perennial plant from southern Africa

Aristaloe is a genus of evergreen flowering perennial plants in the family Asphodelaceae from Southern Africa. Its sole species is Aristaloe aristata, known as guinea-fowl aloe or lace aloe.

<i>Haworthia</i> Genus of flowering plants

Haworthia is a large genus of small succulent plants endemic to Southern Africa (Mozambique, Namibia, Lesotho, Eswatini and South Africa).

<i>Haworthiopsis venosa</i> Species of succulent

Haworthiopsis venosa, formerly Haworthia venosa, known in Afrikaans as venstertjie, is a species of flowering plant in the genus Haworthiopsis belonging to the family Asphodelaceae, native to Namibia and South Africa.

<i>Tulista</i> Genus of flowering plants

Tulista is a small genus of succulent plants endemic to South Africa. They were formerly included within the genus Haworthia.

<i>Haworthiopsis nigra</i> Species of succulent

Haworthiopsis nigra, formerly Haworthia nigra, is a species of flowering succulent plant from the Western and Eastern Cape Provinces, South Africa.

<i>Haworthiopsis pungens</i> Species of succulent

Haworthiopsis pungens, formerly Haworthia pungens, is a species of flowering succulent plant from the Eastern Cape Province, South Africa.

<i>Haworthiopsis scabra</i> Species of succulent

Haworthiopsis scabra, formerly Haworthia scabra, is a species of flowering succulent plant from arid regions of the Western and Eastern Cape Provinces, South Africa.

<i>Haworthiopsis bruynsii</i> Species of succulent

Haworthiopsis bruynsii, formerly Haworthia bruynsii, is a rare species of the genus Haworthiopsis in the family Asphodelaceae, endemic to a small area in the Eastern Cape Provinces in South Africa.

<i>Haworthiopsis glauca</i> Species of succulent

Haworthiopsis glauca, formerly Haworthia glauca, is a species of flowering succulent plant from the Eastern Cape Province, South Africa.

<i>Haworthiopsis viscosa</i> Species of succulent

Haworthiopsis viscosa, formerly Haworthia viscosa, is a species of flowering succulent plant from the Western and Eastern Cape Provinces, South Africa.

<i>Tulista pumila</i> Species of flowering plant

Tulista pumila ("Vratjiesaalwee") is a species of Tulista succulent plant, from the Western Cape, South Africa.

<i>Tulista kingiana</i> Species of succulent plant from the Western Cape, South Africa

Tulista kingiana is a species of succulent plant, from the Western Cape, South Africa. It is listed as Endangered on the IUCN global Red List

<i>Tulista marginata</i> Species of flowering plant

Tulista marginata is a species of Tulista succulent plant, from the Western Cape, South Africa.

<i>Tulista minor</i> Species of flowering plant

Tulista minor is a species of succulent plant, from the far south of the Western Cape, South Africa.

<i>Gonialoe</i> Genus of succulent flowering plants from southern Africa

Gonialoe is a small genus of three succulent plant species, indigenous to South Africa, Namibia and Angola. They were formerly included within the related genus Aloe. The three species are Gonialoe variegata, Gonialoe sladeniana, Gonialoe dinteri.

<span class="mw-page-title-main">Aloeae</span> Tribe of succulent plants

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 narrower circumscription of Asphodelaceae adopted prior to the APG III system. Typically, plants have rosettes of more or less succulent leaves, with or without a distinct stem. Their flowers are arranged in racemes and tend to be either small and pale, pollinated by insects, or larger and more brightly coloured, pollinated by birds. As of 2017, 11 genera are recognized, most created since 2010 by splitting off another five genera from Aloe and another two from Haworthia. Only two genera, Aloe and Aloidendron, are native outside southern Africa, extending northwards to the Arabian Peninsula. Seven genera are restricted to South Africa, some with small ranges. Members of the Aloeae are cultivated by succulent plant enthusiasts; Aloe species especially are used in temperate climates as ornamental garden plants. Some species are used in traditional medicine. Aloe vera and Aloe ferox are cultivated for their extracts, whose uses include moisturizers and emollients in cosmetics.

<i>Aloidendron</i> Species of plant in the family Asphodelaceae

Aloidendron is a genus of succulent plants in the subfamily Asphodeloideae. It was split off from the much larger genus Aloe in 2013.

References

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  2. Molteno S. (2022), "Phyllotaxis in Asphodelaceae subfam. Alooideae: a tool in taxon delimitation." Haseltonia28(1), https://doi.org/10.2985/026.028.0107
  3. 1 2 3 4 5 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, S2CID   86714657
  4. 1 2 3 4 5 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
  5. Stearn, W.T. (2004), Botanical Latin (4th (p/b) ed.), Portland, Oregon: Timber Press, p. 257, ISBN   978-0-7153-1643-6
  6. Bayer, M.B. (1971), "Changes in the genus Haworthia", Cactus and Succulent Journal (US), 43: 157–162, retrieved 2017-10-18
  7. 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
  8. 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
  9. Rowley, G.D. (2013), "Generic concepts in the Alooideae 3: The phylogenetic story", Alsterworthia International Special Issue, 10: 1–7; cited in Gildenhuys & Klopper (2016) {{citation}}: CS1 maint: postscript (link)
  10. "Search for Haworthiopsis", World Checklist of Selected Plant Families , Royal Botanic Gardens, Kew , retrieved 2017-10-16