If you have ever owned a “zebra plant” — a small, dark green Alooid with white stripes — you have owned a Haworthiopsis. The genus may be unfamiliar, but its most famous member, Haworthiopsis attenuata, is one of the most widely sold succulents on Earth — produced by the million, stocked in every garden centre, surviving on windowsills from Tokyo to Toronto with a tenacity that borders on the indestructible. It is, for many people, the very first succulent they ever own.
Yet Haworthiopsis is more than the zebra plant. The genus contains approximately eighteen species of hard-leaved, often beautifully tuberculate succulents, all endemic to southern Africa, ranging from the familiar striped rosettes to tall columnar spirals, file-textured fans and dark, enigmatic rarities that look like nothing else in the plant kingdom. They share the shade tolerance and compact size of their soft-leaved relatives in Haworthia, but their harder, tougher leaves give them a resilience that makes them even easier to grow — the ideal succulents for beginners, indoor gardeners and anyone who wants a plant that forgives mistakes.
This page is the reference for the genus Haworthiopsis on our site. It covers taxonomy, the separation from Haworthia, all accepted species organised by section, cultivation and the resources that every grower needs.
Taxonomy and classification
From Haworthia to Haworthiopsis
For over two centuries, the hard-leaved species now placed in Haworthiopsis were classified within the genus Haworthia, in the subgenus Hexangulares (Bayer 1971). They were always recognised as morphologically distinct from the soft-leaved, windowed species of subgenus Haworthia — their leaves are firmer, harder, with a thicker epidermis, often bearing prominent white tubercles or ridges, and their flowers differ in subtle but consistent ways. But until molecular data became available, there was no strong reason to separate them at the genus level.
That changed in the 2010s. Multiple phylogenetic studies showed that subgenus Hexangulares was more closely related to Gasteria — the stomach-flowered aloe relatives — than to the soft-leaved species of subgenus Haworthia. In other words, a Haworthiopsis attenuata is a closer evolutionary cousin to a Gasteria than to a Haworthia cooperi. Keeping them in the same genus was phylogenetically untenable.
In 2013, Gordon Rowley erected the genus Haworthiopsis (meaning “resembling Haworthia“) for the species of subgenus Hexangulares, with Haworthiopsis coarctata as the type species. Manning et al. (2014) refined the circumscription, and Gildenhuys and Klopper (2016) produced the definitive synoptic review — dividing the genus into five sections with keys, descriptions and distribution maps for all accepted species. Woudstra et al. (2025) confirmed the monophyly of the genus using nuclear phylogenomics.
Position in the alooid group
Haworthiopsis belongs to the family Asphodelaceae, subfamily Asphodeloideae, within the alooid clade. Its closest relative is Gasteria — the two genera form a well-supported sister pair in all published molecular phylogenies. More distantly related are Tulista (the robust haworthioids), Astroloba, Aristaloe, Gonialoe and the soft-leaved Haworthia sensu stricto.
The name
The genus name Haworthiopsis combines Haworthia with the Greek suffix -opsis (“appearance, resemblance”) — literally “looking like Haworthia.” The name reflects the long history of these species being classified within Haworthia, while acknowledging that they are now recognised as a distinct evolutionary lineage. In nurseries and the horticultural trade, the old names (Haworthia attenuata, Haworthia fasciata, etc.) remain overwhelmingly dominant — expect to encounter both old and new nomenclature for years to come.
How to distinguish Haworthiopsis from Haworthia and Tulista
For the grower, the distinction is straightforward:
Haworthia (the soft-leaved haworthias): leaves are soft, fleshy, often translucent or windowed. Leaf surface is usually smooth (no raised tubercles). The plant looks delicate, almost gem-like. Flowers have a curved tube and are triangular in cross-section.
Haworthiopsis (the hard-leaved haworthias): leaves are firm, hard, with a thicker epidermis. Many species have prominent white tubercles — raised bumps or ridges on the leaf surface (the “zebra stripes”). The plant looks tough, architectural. Flowers have straight styles and taper smoothly into the pedicel (no sharp junction at the base). Flower tube is six-sided in cross-section.
Tulista (the robust haworthioids): much larger than either of the above — rosettes to twenty centimetres or more. Densely covered in pearly white tubercles. Flowers have distinctively robust, thick peduncles. Only four species exist.
In practice, if your plant has hard leaves with white stripes or bumps and fits in the palm of your hand, it is almost certainly a Haworthiopsis.
Distribution
Haworthiopsis is endemic to southern and eastern Africa. The centre of diversity is the Eastern Cape Province of South Africa — particularly the area between Makhanda (Grahamstown) and Port Elizabeth, which is also the core range of Gasteria (consistent with their close phylogenetic relationship). Several species have wider distributions: Haworthiopsis tessellata occurs across much of South Africa, and Haworthiopsis limifolia — the geographic outlier of the genus — is found far to the east, in Mpumalanga, KwaZulu-Natal and Eswatini (Swaziland).
In habitat, Haworthiopsis species grow in sheltered positions: in the shade of bushes, between rocks, on cliff faces, in the dappled light of thicket vegetation. Like their Haworthia relatives, they are understorey plants adapted to filtered light and thin, rocky soils. Some species (H. reinwardtii, H. coarctata) grow in more exposed positions, forming columnar clusters in rocky grassland.
Morphology
Leaves: firm, hard, succulent, with a thicker epidermis than Haworthia sensu stricto. Shape varies from triangular (in rosette-forming species like H. attenuata) to ovate-lanceolate (pressed against the stem in columnar species like H. reinwardtii). The most distinctive feature of many species is the white tubercles — raised bumps or ridges composed of calcium oxalate crystals, arranged in transverse bands (the “zebra” pattern), scattered across the surface, or forming continuous ridges. Tubercles may be smooth, pointed or almost spine-like. Not all species are tuberculate — H. glauca is smooth and blue-grey, and H. tessellata has a mosaic pattern of raised lines rather than discrete bumps.
Growth forms: two main types. Rosette-forming species (H. attenuata, H. fasciata, H. limifolia) produce compact, stemless rosettes of five to fifteen centimetres. Columnar species (H. reinwardtii, H. coarctata, H. glauca) produce elongated stems with leaves spiralling around the axis, reaching twenty to thirty centimetres tall and often clustering from the base.
Flowers: small (less than seventeen millimetres), pale — white to pinkish-white with greenish or brownish central veins on the tepals. Borne on slender, erect to arching scapes. The flower tube is six-sided in cross-section (not triangular as in Haworthia), and the style is usually straight (not curved). Pollinated by proboscis flies and small bees.
Roots: succulent, shallow — an adaptation to thin, rocky soils.
Size: small to medium. Most species form rosettes or columns of five to twenty centimetres. The smallest species (H. fasciata in some forms) may be barely five centimetres across. The tallest columnar species (H. reinwardtii, H. coarctata) can reach thirty centimetres.
Cultivation: tough, shade-tolerant, nearly indestructible
Haworthiopsis species are among the most forgiving succulents in cultivation. Their hard leaves and thick epidermis give them a margin of error that the soft-leaved Haworthia species do not have — they tolerate more light, more drought, more neglect and more irregular watering than almost any other succulent genus.
Light: bright indirect light is ideal. Haworthiopsis species tolerate more sun than Haworthia sensu stricto — the columnar species (H. reinwardtii, H. coarctata) can even handle morning sun or dappled sun all day. However, hot afternoon sun can still scorch the leaves, particularly the rosette species. Indoors, an east or north-facing window is perfect. They also tolerate lower light than most succulents — surviving (though not thriving) in offices and rooms without direct sun.
Substrate: well-drained, gritty. A mix of 50 % mineral material (pumice, perlite, coarse sand) and 50 % quality potting compost. Standard cactus and succulent mix is perfectly adequate. Haworthiopsis is less fussy about substrate than Haworthia — it tolerates slightly heavier mixes without rotting, though fast drainage remains important.
Watering: moderate. Water when the substrate is dry — typically every one to two weeks in the growing season (spring and autumn), less in summer heat and winter cold. Haworthiopsis tolerates missed waterings remarkably well — the hard leaves shrivel slightly but recover fully once water is provided. Overwatering is the main risk, particularly in winter.
Temperature: comfortable between 5 and 35 °C. Most species tolerate brief frost to -2/-3 °C in dry soil — slightly hardier than Haworthia sensu stricto. H. tessellata, with its wide distribution across South Africa, is among the hardiest, tolerating light frost routinely. In frost-prone climates, grow indoors or in a cool greenhouse.
Growing season: bimodal — spring and autumn. Most species slow down in summer heat and winter cold. The best growth and flowering occurs during the transitional seasons when temperatures are moderate (15–25 °C).
Indoor growing
Haworthiopsis species are among the top three genera for indoor succulent culture — alongside Haworthia and Gasteria. Their shade tolerance, compact size and drought resistance make them ideal for windowsills, desks, bookshelves and bathrooms with some natural light. Haworthiopsis attenuata in particular has earned its reputation as the “unkillable” succulent — it survives conditions that would kill cacti, aloes and most other succulents.
Indoor hazards: overwatering (always err on the dry side), mealybugs (inspect regularly — both aerial and root mealybugs affect Haworthiopsis) and etiolation (if light is too low, rosettes will stretch and lose their compact form).
Propagation
From offsets: the easiest method. Most Haworthiopsis species sucker prolifically from the base, producing offsets that can be detached with a sharp knife and potted individually. H. attenuata, H. fasciata and the columnar species are particularly generous offsetters. Best done in spring.
From leaf cuttings: more reliable in Haworthiopsis than in Haworthia — the harder leaves are less prone to rotting before rooting. Detach a healthy leaf cleanly from the base, allow the wound to dry for a few days, lay on moist substrate. A tiny plantlet emerges from the base within weeks to months.
From stem cuttings: applicable to the columnar species (H. reinwardtii, H. coarctata, H. glauca). Cut a section of stem, allow to dry, plant in substrate. Roots and new growth emerge readily.
From seed: germination is rapid at 20–25 °C. Seedlings are tiny and slow-growing. Note: Haworthiopsis hybridises easily with other Haworthiopsis species, with Gasteria (producing ×Gasterhaworthia) and even with Aloe. Open-pollinated seed may produce hybrids.
Pests and diseases
Mealybugs: the most common pest — both aerial (white cottony masses at leaf bases) and root mealybugs (feeding underground, invisible until the plant declines). Root mealybugs are particularly problematic in collections. Treatment: isopropyl alcohol for aerial infestations, systemic insecticide (where available) or root drenches for root mealybugs. Prevention: inspect new acquisitions, quarantine before introducing to your collection.
Root rot: from overwatering, especially in winter or in poorly drained substrate. The hard leaves make Haworthiopsis more resistant to crown rot than Haworthia, but root rot can still kill. Prevention: proper substrate, drainage holes, watering discipline.
Sunburn: white or brown patches from excessive direct sun. Move to a shadier position. The marks are permanent on the affected leaves but new growth will be normal.
Black spot: less common in Haworthiopsis than in Gasteria, but occasionally seen. Circular black depressions on the leaves. Cosmetic rather than fatal. Improve air circulation.
Species list
The genus Haworthiopsis contains eighteen accepted species and twenty-five infraspecific taxa (following Gildenhuys & Klopper 2016, with subsequent updates). Species are organised below by the seven sections proposed by Gildenhuys & Klopper, defined by combinations of leaf, flower and seed morphology supported by molecular data. Conservation status follows the South African Red List (SANBI).
Section Attenuatae Gildenh. & Klopper
Rosette-forming species with triangular, ascending leaves bearing prominent white tubercles arranged in transverse bands on the outer (abaxial) surface.
Haworthiopsis attenuata (Haw.) G.D. Rowley (syn. Haworthia attenuata) — Eastern Cape (widespread, from Makhanda to Port Elizabeth and beyond). The zebra plant. The most commercially important haworthioid species — produced in enormous quantities for the global houseplant market. Dark green, triangular leaves with bold white tubercle bands on the outer surface; the inner surface also bears tubercles (unlike H. fasciata). Rosettes typically six to twelve centimetres in diameter. Suckering, forming dense clusters. Extremely easy to grow — tolerates neglect, low light, dry air and irregular watering. Numerous cultivated forms: ‘Super White’ (very dense, bright white banding covering most of the leaf surface), ‘Radula’ (fine, sandpaper-like tubercles instead of bold bands), ‘Enon’ (narrow leaves with fine banding), variegated forms. Conservation: Vulnerable (VU) in the wild despite commercial abundance — wild populations are threatened by urban expansion and illegal collecting.
Section Haworthiopsis Gildenh. & Klopper
Species with leaves arranged in a spiral around an elongated stem — the columnar haworthioids. This section also includes H. fasciata, which, despite being rosette-forming, is phylogenetically closer to the columnar species than to H. attenuata.
Haworthiopsis fasciata (Willd.) G.D. Rowley (syn. Haworthia fasciata) — Eastern Cape (near Makhanda). Very similar to H. attenuata in general appearance — dark green leaves with white tubercle bands. The key diagnostic difference: the inner (adaxial) leaf surface is smooth, without tubercles. In the trade, the two species are routinely confused — many plants sold as “Haworthia fasciata” are actually H. attenuata. True H. fasciata has a more restricted natural range. Conservation: Near Threatened (NT).
Haworthiopsis coarctata (Haw.) G.D. Rowley (syn. Haworthia coarctata) — Eastern Cape. The type species of the genus. Columnar, with leaves tightly pressed against the stem in a dense spiral. Leaves dark green with white tubercles, often in rows. Offsets freely, forming clusters. Several varieties: var. coarctata (typical), var. tenuis (thinner leaves). Conservation: Least Concern (LC).
Haworthiopsis reinwardtii (Salm-Dyck) G.D. Rowley (syn. Haworthia reinwardtii) — Eastern Cape. Columnar, with leaves more loosely arranged and slightly spreading from the stem. White tubercles prominent, sometimes pointed. Several varieties, including var. zebrina (bold transverse banding) and var. brevicula. One of the most architectural small succulents. Conservation: Least Concern (LC).
Haworthiopsis glauca (Baker) G.D. Rowley (syn. Haworthia glauca) — Eastern Cape. Distinctive columnar species with smooth, blue-grey leaves without prominent tubercles. Narrow, ascending leaves with a glaucous bloom. Variety herrei (Poelln.) M.B. Bayer has narrower leaves. The most elegant of the columnar species. Conservation: Least Concern (LC).
Haworthiopsis longiana (Poelln.) G.D. Rowley (syn. Haworthia longiana) — Eastern Cape. Long, narrow, dark green leaves with fine white margins arranged loosely around an elongated stem. Uncommon in cultivation. Conservation: Endangered (EN).
Section Viscosae Gildenh. & Klopper
Species with leaves arranged in three distinct ranks (trifarious) along an elongated stem — a distinctive leaf arrangement unique to this section within the genus. Leaves are typically roughened (scabrous) rather than bearing discrete white tubercles.
Haworthiopsis viscosa (L.) Gildenh. & Klopper (syn. Haworthia viscosa) — widespread across the Eastern, Western and Northern Cape (Karoo, Little Karoo, Gamtoos Valley). One of the most distinctive haworthioids: leaves arranged in three precise ranks along a short, stiff stem, giving the plant a triangular cross-section. Leaves are small, hard, dark green to brownish-green, with a rough, slightly sticky surface (hence the name viscosa). Slow-growing but hardy, forming dense clusters over time. Extremely variable — G.G. Smith described fifteen varieties. Hybridises readily with several species in nature. Conservation: Least Concern (LC).
Haworthiopsis nigra (Haw.) G.D. Rowley (syn. Haworthia nigra) — Eastern Cape. Similar to H. viscosa in its trifarious leaf arrangement, but leaves are darker (greenish-black to brownish-black — hence nigra), rougher and more strongly keeled. The darkest-leaved species in the genus. Two varieties: var. nigra (typical) and var. diversifolia (Poelln.) G.D. Rowley (more variable leaf shapes). Conservation: Least Concern (LC).
Section Scabrae Gildenh. & Klopper
A section for a single variable species with rough (scabrous), ascending, distichous to rosulate leaves.
Haworthiopsis scabra (Haw.) G.D. Rowley (syn. Haworthia scabra) — Western and Southern Cape (widespread in the Little Karoo and surroundings). Compact rosettes to stems with ascending, rough-surfaced, dark green to brownish leaves. Extremely variable — four varieties: var. scabra (typical), var. lateganiae (Poelln.) M.B. Bayer, var. morrisiae (Poelln.) M.B. Bayer and var. starkiana (Poelln.) G.D. Rowley. Hybridises with H. viscosa in nature (the hybrid was described as H. tauteae). Conservation: Least Concern (LC).
Section Limifoliae Gildenh. & Klopper
A monotypic section defined by the distinctive transverse ridges on the leaf surface — like the teeth of a file.
Haworthiopsis limifolia (Marloth) G.D. Rowley (syn. Haworthia limifolia) — Mpumalanga, KwaZulu-Natal, Eswatini. The file-leaved haworthia. The geographic outlier of the genus — found far to the east in the summer-rainfall subtropical lowveld. Broad rosettes of dark green, triangular leaves with distinctive raised transverse ridges that feel like a coarse file. Rosettes to fifteen centimetres. Suckering. Several varieties: var. limifolia (typical), var. ubomboensis (smaller, finer ridges), var. gigantea (larger). Named cultivars: ‘Lime Green’, ‘Fairy Washboard’, variegated forms. Conservation: Vulnerable (VU) — wild populations threatened by medicinal harvesting and habitat destruction.
Section Koelmaniorum Gildenh. & Klopper
A monotypic section containing a taxonomically enigmatic species. Molecular studies place it uncertainly — some analyses group it with Haworthiopsis, others with Tulista.
Haworthiopsis koelmaniorum (Oberm. & D.S. Hardy) Boatwr. & J.C. Manning (syn. Haworthia koelmaniorum) — Mpumalanga. Dark green to brownish, rough, warty leaves with a leathery texture unlike any other Haworthiopsis. Rosettes to ten centimetres. Does not offset easily. Variety mcmurtryi (Oberm. & D.S. Hardy) M.B. Bayer has smoother, more glossy leaves. Rare in cultivation. Conservation: Vulnerable (VU).
Section Tessellatae Gildenh. & Klopper
Species with a distinctive mosaic or tessellated pattern of raised lines on the upper leaf surface — a network of translucent lines surrounding opaque islands.
Haworthiopsis tessellata (Haw.) G.D. Rowley (syn. Haworthia tessellata) — widespread across South Africa (Eastern Cape to Northern Cape and Limpopo — the widest distribution of any Haworthiopsis). Compact rosettes of brownish-green leaves with a distinctive tessellated (mosaic-patterned) upper surface. Very variable across its range. Easy to grow, drought-tolerant, tolerates more sun than most haworthioids. Among the hardiest species. Conservation: Least Concern (LC).
Haworthiopsis venosa (Lam.) G.D. Rowley (syn. Haworthia venosa) — Eastern Cape. Similar to H. tessellata but with more prominent venation and a more restricted distribution. Compact rosettes. Conservation: Vulnerable (VU).
Haworthiopsis granulata (Marloth) G.D. Rowley (syn. Haworthia granulata) — Western and Eastern Cape. Compact rosettes with finely granulated (sandpaper-like) leaf surfaces — densely packed raised points rather than larger tubercles or mosaic lines. A distinctive texture. Conservation: Least Concern (LC).
Haworthiopsis woolleyi (Poelln.) G.D. Rowley (syn. Haworthia woolleyi) — Eastern Cape (very restricted range). A small, compact species with tessellated patterning. Rare in habitat and in cultivation. Conservation: Critically Endangered (CR) — the most threatened species in the genus.
Haworthiopsis bruynsii (M.B. Bayer) G.D. Rowley (syn. Haworthia bruynsii) — Eastern Cape. A distinctive, small species with soft, almost translucent leaves — an exception to the “hard-leaved” characterisation of the genus. Compact rosettes barely five centimetres across. Highly sought-after. Conservation: Endangered (EN).
Haworthiopsis sordida (Haw.) G.D. Rowley (syn. Haworthia sordida) — Eastern Cape. Robust, dark green, rough, slightly tessellated leaves. Compact rosettes. Variety lavranii Scott. Conservation: Near Threatened (NT).
Haworthiopsis pungens (M.B. Bayer) Boatwr. & J.C. Manning (syn. Haworthia pungens) — Eastern Cape. Firm, pointed leaves with raised ridges. Compact rosettes. Conservation: Vulnerable (VU).
Choosing Haworthiopsis for your collection
For absolute beginners: Haworthiopsis attenuata — the zebra plant. Nearly impossible to kill. Start here. The cultivar ‘Super White’ is particularly striking if you can find it.
For windowsill culture: Haworthiopsis attenuata, Haworthiopsis fasciata, Haworthiopsis limifolia. All three are compact, shade-tolerant and forgiving.
For architectural collectors: Haworthiopsis reinwardtii (tall spiralling columns), Haworthiopsis glauca (elegant blue-grey columns), Haworthiopsis coarctata (dense, textured columns). These species make an impact as standalone specimens.
For pattern lovers: Haworthiopsis tessellata (mosaic pattern, reptilian texture), Haworthiopsis limifolia (file ridges), Haworthiopsis attenuata ‘Super White’ (bold banding).
For rare-plant hunters: Haworthiopsis koelmaniorum (dark, warty, enigmatic), Haworthiopsis bruynsii (soft-leaved exception), Haworthiopsis woolleyi (rare tessellated miniature).
Hybridisation
Haworthiopsis hybridises readily — among its own species, with Gasteria (producing ×Gasterhaworthia hybrids), with Aloe, with Astroloba and with Haworthia sensu stricto. In cultivation, intergeneric hybrids — particularly ×Gasterhaworthia — are popular: they combine the compact habit and shade tolerance of Haworthiopsis with the distinctive flower shapes and leaf textures of Gasteria.
The most widely known hybrid involving Haworthiopsis is probably ×Gasteraloe ‘Green Ice’ — often attributed to a cross between Gasteria carinata var. verrucosa and Aristaloe aristata, but the exact parentage is debated. Many unnamed ×Gasterhaworthia hybrids circulate in the trade.
For collectors, the ease of hybridisation is a caution: any Haworthiopsis grown from open-pollinated seed may be a hybrid, especially if other genera were flowering nearby. If species purity matters, controlled pollination is necessary.
Web resources
Plants of the World Online (POWO) — Kew Royal Botanic Gardens. The authoritative database for accepted names, synonymy and distribution. The first place to check any name.
Haworthia Updates (haworthiaupdates.org). M.B. Bayer’s website — decades of articles, taxonomic revisions and field observations covering all haworthioid genera. The most important online resource on haworthioid systematics.
The Haworthia Society (haworthia.org). International society publishing Haworthiad quarterly. Covers Haworthiopsis extensively. Species checklists, cultivation guides, specialist publications.
PlantZAfrica — South African National Biodiversity Institute (SANBI). Specialist genus pages with distribution data, morphological descriptions and habitat photographs.
Haworthia-Gasteria blogspot (haworthia-gasteria.blogspot.com). Kuba’s comprehensive identification aid with photographs from habitat and cultivation. Strong on Haworthiopsis species and their variability.
Llifle — Encyclopaedia of Succulents (llifle.com). Cultivation notes and photographs for many species. Variable quality but useful.
iNaturalist (inaturalist.org). Citizen-science observations with photographs and GPS data. Valuable for understanding variation and distribution in the wild.
Bibliography
The definitive revision
Gildenhuys S.D., Klopper R.R. (2016). A synoptic review of the genus Haworthiopsis. Bradleya, 34: 2–57. — The essential reference for the genus. Keys, descriptions, distribution maps and photographs for all accepted species, varieties and sections. Any serious Haworthiopsis grower should obtain this paper.
Taxonomy and phylogenetics
Rowley G.D. (2013). Generic concepts in Alooideae. Part 7 — Haworthiopsis. Alsterworthia International, Special Issue 10. — The original description of the genus.
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. Systematic Botany, 39(1): 55–74. — The paper that established the phylogenetic framework for the separation of Haworthiopsis from Haworthia.
Woudstra Y., Grace O.M., Klopper R.R. et al. (2025). Nuclear phylogenomics reveals strong geographic patterns in the evolutionary history of Aloe and related genera (alooids). Annals of Botany. — Confirms the monophyly of Haworthiopsis using nuclear genome data.
Zonneveld B.J.M. (2015). Nuclear genome sizes of 343 accessions of wild-collected Haworthia (Asphodelaceae, Alooideae). Plant Systematics and Evolution, 301: 1405–1424. — Genome size data supporting the generic-level separation.
General references
Bayer M.B. (1999). Haworthia Revisited. Umdaus Press, Hatfield. — Although predating the separation of Haworthiopsis, this monograph remains valuable for its species descriptions and distribution data for the taxa now placed in Haworthiopsis.
Bayer M.B. (2009). Haworthia Update. Vol. 1–5. — Updates to the 1999 monograph, with additional field observations and taxonomic notes.
Breuer I. (2010). The World of Haworthias. Volumes 1–2. Self-published, Germany. — An alternative treatment with more taxa recognised. Extensively illustrated.
Schulz R. (2009). Haworthia for the Collector. — Practical cultivation guide covering Haworthiopsis alongside Haworthia and Tulista.
Going further
The genus Haworthiopsis is small — eighteen species — but it punches far above its weight in horticulture. It includes the most commercially important haworthioid (H. attenuata), some of the most architectural small succulents (the columnar species) and some of the most intriguing botanical puzzles (the enigmatic H. koelmaniorum). All species are compact, shade-tolerant, drought-resistant and almost indestructible in cultivation — the ideal succulents for anyone who wants beautiful plants without drama. Our site offers detailed species profiles, care guides and pest management advice for every commonly cultivated Haworthiopsis.