Haworthiopsis attenuata is, in all probability, the single most widely cultivated species in the genus Haworthiopsis and one of the most popular small succulents on Earth. Sold by the million as the “zebra plant,” “zebra haworthia,” or simply “haworthia,” this compact, rosette-forming succulent from the Eastern Cape of South Africa appears in starter kits, terrariums, office desks and gift sets on every continent. It is almost universally mislabelled: the vast majority of plants sold under the name Haworthiopsis fasciata are in fact Haworthiopsis attenuata, which is far more common in commerce. The true Haworthiopsis fasciata is rare in cultivation. This article describes the real Haworthiopsis attenuata, explains how to distinguish it from Haworthiopsis fasciata, documents its remarkable infraspecific variation, and provides a complete guide to cultivation, including the species’ conservation status — which is more precarious than its commercial ubiquity might suggest.
Taxonomy and nomenclature
Haworthiopsis attenuata (Haw.) G.D.Rowley was published in Haseltonia 19: 43 (2013), as part of the reclassification that split the old genus Haworthia into three: Haworthia sensu stricto (soft-leaved, windowed species), Haworthiopsis (hard-leaved, tuberculate species), and Tulista. The species was originally described as Aloe attenuata by Haworth in 1804, then transferred to Haworthia attenuata (Haw.) Haw. in 1812.
The species epithet attenuata means “thinned” or “tapering” in Latin, referring to the leaves that narrow gradually to a pointed tip.
The infrageneric classification of Haworthiopsis attenuata was revised by Gildenhuys and Klopper (2016, Phytotaxa 265: 1–26). Two varieties are currently recognised: Haworthiopsis attenuata var. attenuata (the type) and Haworthiopsis attenuata var. radula (Jacq.) G.D.Rowley — previously treated as a separate species (Haworthia radula), which has longer, more elongated leaves with smaller, more numerous tubercles. A third taxon, Haworthiopsis attenuata var. glabrata, has been treated by some authors as the separate species Haworthia glabrata.
Historically, the species was described and redescribed under numerous names reflecting the extraordinary range of tubercle patterns found across its distribution. The form clariperla (with large, pearl-like white tubercles forming confluent bands) and the form variegata (with yellow, white, pink or orange longitudinal striping) are among the most sought-after by collectors.
Ecology and habitat
Haworthiopsis attenuata is endemic to the Eastern Cape Province of South Africa, distributed from the Gamtoos River in the west to the Mbashe River in the east — a range of approximately 300 kilometres along the coast and inland valleys. It is the most widespread species in the genus.
The species grows in Valley Bushveld and Albany Thicket vegetation, among rocks, grasses and under shrubs. Like Haworthiopsis fasciata, it is a shade-dwelling species — it grows in the partial shade of larger plants and rock outcrops, rarely in full sun. PlantZAfrica (SANBI) notes that it has “fleshy leaves that store water, which gives the plant the ability to survive dry periods and droughts.”
The climate across its range is mild and frost-free, with rainfall distributed year-round (neither strictly winter nor summer). The substrate is typically rocky, well-drained, with a mixture of sandy and loamy soils.
Conservation status
Despite its commercial abundance, Haworthiopsis attenuata is assessed as Vulnerable (VU) on the South African Red List. The SANBI Red List estimates at least a 30 % population decline over the past century due to habitat loss (urban and industrial expansion around Port Elizabeth/Gqeberha) and intensive harvesting for traditional medicine (intelezi — plants used to ward off evil spirits). A further 20 % decline is anticipated in the next decade due to planned land clearing and continued medicinal harvesting.
This is a sobering reminder that commercial propagation does not protect wild populations. The millions of Haworthiopsis attenuata on windowsills worldwide are almost entirely nursery-propagated; the wild populations face an entirely separate set of threats.
Description
Haworthiopsis attenuata is a small, stemless, evergreen, clumping succulent. Individual rosettes contain 30 to 40 dark green, fleshy leaves and measure 6 to 15 cm (2.5–6 in) in diameter and 5 to 12 cm (2–5 in) in height. The species offsets prolifically, forming dense mats or clumps in the wild.
The leaves are lanceolate, erect to spreading, tapering gradually to a pointed tip. They are covered with raised white tubercles on both the inner (adaxial) and outer (abaxial) surfaces — this is the defining diagnostic character that separates Haworthiopsis attenuata from Haworthiopsis fasciata, which has tubercles on the outer surface only. The tubercle pattern varies enormously across the species’ range: from scattered, isolated dots to dense, confluent horizontal bands (the “zebra” pattern), to near-uniform pearly white coverage (the clariperla form).
The leaves are not fibrous (they do not tear into longitudinal fibres when broken) — a second distinction from Haworthiopsis fasciata, whose leaves are fibrous.
In bright light, the dark green leaves may develop copper, reddish or purplish tones — a stress-related pigmentation that many collectors consider attractive.
The inflorescence is a slender, unbranched raceme up to 40 cm (16 in) long, bearing small, white, tubular flowers with green veining. Flowering occurs in late spring to early summer (November–December in the Southern Hemisphere).
Comparison: Haworthiopsis attenuata vs Haworthiopsis fasciata
This is the identification that every succulent grower should be able to make. Both species form small, dark green rosettes with horizontal bands of white tubercles on the leaves, and both are commonly sold as “zebra plant.” They can be reliably distinguished by two characters:
Tubercle distribution (the quick test): run your finger over the inner (upper, concave) surface of a leaf. If it feels rough and bumpy, you have Haworthiopsis attenuata. If it is completely smooth, you have Haworthiopsis fasciata.
Leaf fibrousness (the definitive test): break a leaf and pull it apart. If the tissue tears into longitudinal fibres, it is Haworthiopsis fasciata. If it snaps cleanly without fibrous strands, it is Haworthiopsis attenuata.
In addition, Haworthiopsis attenuata typically has longer, thinner, more spreading leaves than Haworthiopsis fasciata, whose leaves tend to be stouter, more deltoid, and more incurved.
Cultivation
Light
Bright indirect light to semi-shade. Haworthiopsis attenuata tolerates a wider light range than most succulents, performing well in east-facing, west-facing or even north-facing windows. Direct midday sun in summer can cause leaf bleaching (leaves turn white or yellowish) — this is cosmetic rather than fatal but is best avoided.
The species is one of the best succulents for low-light indoor environments. However, some bright light is needed to maintain the vivid dark green / white tubercle contrast and to bring out the copper-red stress colouration that collectors prize.
Soil
Well-drained succulent substrate: 50 % coarse mineral material (perlite, pumice, coarse sand) and 50 % organic component. Standard commercial succulent and cactus mixes work well.
Watering
Water evenly and generously during the active growth period (spring and autumn), allowing the substrate to dry completely between waterings. Reduce in summer (semi-dormancy in hot climates) and water sparingly in winter. The species is drought-tolerant and survives neglect far better than overwatering.
Temperature
Ideal range: 15 to 27 °C (60 to 80 °F). NC State Extension reports USDA zones 9 to 11 for outdoor cultivation — slightly hardier than Haworthiopsis fasciata (zones 10–11). The species tolerates brief dips to approximately −1 °C (30 °F) but should not be exposed to sustained frost. Below 10 °C (50 °F), growth slows.
Propagation
Offsets: the easiest and most reliable method. The species offsets prolifically. Separate pups when they have developed several leaves and visible roots. Allow the cut to callous for 24 to 48 hours, then plant in dry substrate.
Leaf cuttings: possible. Remove an intact leaf cleanly, allow to callous, place cut end in substrate. Slower than offsets but feasible.
Seed: small, slow, rarely used. Sow on moist, well-drained seed-starting mix at 20–25 °C.
Pests
Mealybugs and scale insects are the most common pests. Root mealybugs (white, cottony masses in the root zone) are an occasional problem that can go undetected until the plant declines. Treatment: unpot, wash roots, drench with systemic insecticide, repot in fresh substrate.
Non-toxicity
Haworthiopsis attenuata is non-toxic to cats, dogs and humans — one of the few succulents that is genuinely safe in a household with pets and small children.
Cold hardiness
NC State Extension reports USDA zones 9 to 11, making Haworthiopsis attenuata marginally hardier than Haworthiopsis fasciata (zones 10–11). World of Succulents records a minimum of 30 °F (−1 °C). In practice, both species should be treated as houseplants in any climate with regular frost.
The difference matters in zone 9b (minimum −4 to −1 °C): Haworthiopsis attenuata may survive sheltered outdoor positions in this zone where Haworthiopsis fasciata would not.
Traditional use
SANBI documents that Haworthiopsis attenuata is one of the most heavily traded species in South African muthi (traditional medicine) markets, particularly in the Eastern Cape. It is used as an intelezi plant — believed to ward off evil spirits and lightning. During historical periods, it was reportedly used to make warriors fearless. When Haworthiopsis attenuata is unavailable in muthi markets, Haworthiopsis fasciata, Haworthiopsis coarctata and even Aristaloe aristata are used as substitutes. This intense harvesting pressure is the primary driver of the species’ Vulnerable conservation status.
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.
Gildenhuys, S.D. (2017). Haworthiopsis — an illustrated taxonomy. Aloe 53(1): 4–78.
Bayer, M.B. (1999). Haworthia Revisited. Umdaus Press.
SANBI PlantZAfrica. Haworthiopsis attenuata. https://pza.sanbi.org/haworthiopsis-attenuata
SANBI Red List. Haworthiopsis attenuata. https://redlist.sanbi.org/species.php?species=15464-3
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.