Encephalartos lebomboensis

Encephalartos lebomboensis, the Lebombo cycad, is a large southern African cycad with glossy green leaves and toothed leaflets, which grows on cliffs and rocky slopes of the Lebombo Mountains and the Pongola valley, where north-eastern South Africa meets Eswatini and the Mozambique border. This species of the genus Encephalartos, described in 1949 by Inez Verdoorn, long covered all the cycads of the Lebombo; in 1996 Piet Vorster split off Encephalartos senticosus, and many plants grown as “lebomboensis” in fact belong to that second species. Listed as Endangered by the IUCN, it has lost at least half of its wild population, mainly to collectors. In cultivation it has a reputation as an easy, fairly fast cycad that tolerates light frost.

Key facts about Encephalartos lebomboensis

  • Accepted name: Encephalartos lebomboensis I.Verd. (1949), accepted by The World List of Cycads (version 2026.08.15), GBIF and Species+
  • Former names and synonyms: no synonym; until 1996 the name also covered the plants now called Encephalartos senticosus Vorster
  • Family: Zamiaceae, order Cycadales
  • Common names: Lebombo cycad (PlantZAfrica, Species+), a name also applied to Encephalartos senticosus
  • Natural range: South Africa, Eswatini and Mozambique, in fragmented subpopulations; The World List of Cycads gives KwaZulu-Natal for South Africa, while Vorster (1996), PlantZAfrica, SANBI and the 2017 national management plan also cite Mpumalanga; extent of occurrence about 3,900 km² (SANBI, 2023)
  • IUCN status: Endangered (EN A2acd; B1ab(ii,iii,v)+2ab(ii,iii,v)), assessment by J.D. Bösenberg dated May 2020, published in 2022
  • CITES and other protection: CITES Appendix I (whole genus, since 1977); Annex A in the European Union, with a negative EU opinion on artificially propagated plants from South Africa since 2013; included in South Africa’s Biodiversity Management Plan for threatened Encephalartos (2017)
  • Documented hardiness: withstands light frost but may be damaged by heavy frost (PlantZAfrica); grown in the ground for several years on the coast of the Var, in south-east France (2012); no measured minimum published (see Cold hardiness)
  • Light and soil: full sun or light shade, excellent drainage (PlantZAfrica)
  • Habit and adult size: trunk up to 4 m long and about 30 cm across, often reclining; up to eight stems per clump; leaves 1 to 2 m
  • In the UK, US and Australia: Kew, Edinburgh and the National Botanic Garden of Wales (BGCI); Montgomery Botanical Center, the Huntington, Lotusland, the US Botanic Garden and others in the United States; Sydney, Melbourne, Adelaide and Townsville in Australia (BGCI)
  • Toxicity: seeds and tissues should be treated as poisonous, as in other Encephalartos (see Toxicity and precautions)

How to recognise Encephalartos lebomboensis

It is a large green Encephalartos with straight leaves, sometimes curving near the tip, and narrow leaflets toothed on both margins. Verdoorn (1949) describes it as follows, with additions from Dyer (1965) and PlantZAfrica:

  • Trunk: up to 4 m tall and about 30 cm across, with a woolly, domed top; often reclining (PlantZAfrica), single or in clumps of up to eight stems, with many suckers at the base and sometimes on the trunk
  • Leaves: numerous, in a dense crown, ascending to spreading, straight but curved or twisted towards the tip, 1 to 2 m long, light to dark green and glossy (PlantZAfrica); petiole 3 to 10 cm to the first prickle, finely downy at first, then hairless
  • Leaflets: linear-lanceolate, the median ones 12 to 17 cm long and 1.2 to 2.2 cm wide, usually bearing one to four needle-like teeth on both margins, mostly on the lower one, sometimes entire towards the top of the leaf; towards the base of the leaf they are reduced to prickles, first lobed, then straight
  • Male cones: the type cone, apricot yellow and green towards the top, blackening when bruised, measured 46 by 13 cm on a 3 cm stalk (Verdoorn, 1949); PlantZAfrica describes them as narrowly cylindrical, about 45 cm long and 12 to 15 cm across, yellow to apricot, with raised scale faces that are not drawn out into drooping beaks
  • Female cones: apricot yellow or light green, egg- or barrel-shaped, 40 to 45 cm long and 22 to 30 cm across, with almost smooth scales raised about 1 cm and a central depression covered in grey or russet hairs (Verdoorn, 1949; PlantZAfrica)
  • Seeds: with a scarlet fleshy coat, about 4 cm by 1.8 to 2.2 cm (Verdoorn, 1949; Dyer, 1965)

According to Vorster (1996) and PlantZAfrica, the cones of Encephalartos lebomboensis are usually solitary, the female cones sometimes paired in the Mananga form. PlantZAfrica distinguishes two forms: the Piet Retief form, in the south, has shorter, stouter trunks, narrower leaflets and usually solitary, barrel-shaped, greenish-cream female cones; the Mananga form, in the north, has more egg-shaped, apricot-yellow female cones. Jungle Music, a cycad nursery in Encinitas, California, describes both cones as yellow to golden orange and stresses that the narrow leaflets and the petioles are sharply armed.

Encephalartos lebomboensis
Encephalartos lebomboensis grown at the botanical garden of the City of Nice, on the French Riviera.

Hybrids

No natural hybrid is described for Encephalartos lebomboensis in its current sense. Dyer (1965), who took the species in the broad sense, reported near Pongola Poort, where it grows alongside Encephalartos villosus, young plants that suggested natural crossing; that area, around the Jozini dam, now belongs to Encephalartos senticosus according to PlantZAfrica. In cultivation, as with other Encephalartos, hybrids arise whenever several species cone at the same time, and the Royal Botanic Gardens, Kew, declares to BGCI PlantSearch a cultivated Encephalartos lebomboensis × villosus: a plant raised from garden seed is not necessarily pure.

Possible confusion

The essential distinction is with Encephalartos senticosus, which Vorster separated in 1996 and which looks very similar in leaf. According to Vorster’s description (1996), the two species differ mainly in their cones:

  • male cones: usually solitary and stalkless, with scale faces raised into a pyramid, in Encephalartos lebomboensis; three or four per stem, on a stalk up to 10 cm long, with scales drawn out into drooping beaks, in Encephalartos senticosus;
  • female cones: solitary or rarely paired, with almost flat scales, in Encephalartos lebomboensis; two or three per stem, with scale faces raised into a pyramid, in Encephalartos senticosus.

PlantZAfrica (fact sheet on Encephalartos senticosus, 2011) adds that the male cones of Encephalartos senticosus are woolly, those of Encephalartos lebomboensis never, and that its female cones have a rough surface. The 3 cm stalk described by Verdoorn on the male type cone contrasts with the “sessile” cones that Vorster gives for the species; the published sources do not explain the difference. Without cones, identification depends on the origin of the plant, which is rarely known for plants in the trade.

Dyer (1965) separated the species from Encephalartos natalensis, further south, by the smoother, flatter faces of the female cone scales, straighter leaves, a more densely prickly petiole base and narrower leaflets; according to him the two do not overlap, Encephalartos lebomboensis not extending south of the Pongola basin and Encephalartos natalensis not north of the Umfolozi. Verdoorn (1949) separated it from Encephalartos altensteinii, under whose name it circulated, by a smaller plant in every part, narrower leaflets (1 to 2.2 cm against 1.5 to 3.2 cm), always reduced to prickles at the base of the leaf, and less prominent cone scales.

Taxonomy

Encephalartos lebomboensis is an accepted name in The World List of Cycads, GBIF and Species+. Inez Clare Verdoorn described it in December 1949 in The Flowering Plants of Africa (volume 27, plates 1078 and 1079). The type (Keith, National Herbarium Pretoria 28362 a and b, male and female plants) was collected in July 1948 in the garden of Captain D.R. Keith at Ravelston, near Stegi (now Siteki), in Swaziland, on plants brought from a site in the Lebombo Mountains about 7 miles away; Verdoorn also cited collections from Zululand, at Cecil Mack’s Pass and Ingwavuma. The holotype is kept at Pretoria (PRE), with isotypes at the Bolus Herbarium (BOL) and in Durban (NH) (The World List of Cycads).

In 1995 Piet Vorster showed that the name had been misapplied since its publication: in his view it refers to the plants of the Pongola valley and to an isolated population in the Lebombo Mountains of Mpumalanga, whereas the plants of the Lebombo ridge in northern KwaZulu-Natal and Swaziland form a distinct species, which he described in 1996 as Encephalartos senticosus (type: Mlawula reserve, north-east of Siteki). According to Vorster (1996), Encephalartos senticosus occupies the top of the Lebombo from south of the Jozini dam to a few kilometres north of Siteki, where the northern population of Encephalartos lebomboensis takes over; PlantZAfrica places that boundary 50 km north of Siteki. The published sources do not explain how Verdoorn’s type, from near Stegi, relates to this new boundary, and Vorster’s 1995 paper, which deals with the question, could not be consulted. PlantZAfrica also notes that the division of the species into two areas “is debated by some”. This page follows the two species accepted by The World List of Cycads.

Etymology and history

The epithet lebomboensis means “of the Lebombo”, after the Lebombo Mountains (PlantZAfrica; Haynes, 2022, cited by The World List of Cycads).

Verdoorn (1949) tells the story of the description. For more than twenty years Captain Keith had grown at Ravelston an avenue of these cycads taken from the nearby rocky ridges; they had been sold to him as Encephalartos altensteinii, and he had sent plants under that name to Kirstenbosch and to the garden of H.B. Christian in Southern Rhodesia. Henderson had already set them apart in 1945 under the informal name “West’s Cycad”, after a collection by O. West near Ingwavuma. Dyer (1965) notes that in the same garden, female cones had produced in 1947 a carpet of seedlings around the mother plant, a rare event in cultivated Encephalartos.

In the 1960s, before the Jozini dam on the Pongola was filled, several thousand plants were moved by “Operation Wild Flower” and distributed to public gardens and collectors (Dyer, 1965). These plants entered the trade as Encephalartos lebomboensis, but now belong to Encephalartos senticosus (PlantZAfrica), which explains much of the confusion in collections.

Common names

In English, PlantZAfrica and Species+ call it the Lebombo cycad. The Zulu name isiGqiki-somkhovu, “the zombie’s pillow”, given for the species in the broad sense by Palmer and Pitman (1972, quoted by The Gymnosperm Database), is now attached by PlantZAfrica to Encephalartos senticosus, like the name Lebombo cycad and the Afrikaans name lebombobroodboom. A common name is therefore no guide to which of the two species a plant belongs to.

In the wild

The sources do not draw the range in the same way, since not all of them follow the 1996 split:

  • PlantZAfrica describes two areas: in the north, the Lebombo Mountains around Mananga, on the border between Mpumalanga and Eswatini; in the south, the upper Pongola valley around Piet Retief;
  • SANBI’s non-detriment finding document (approved in 2023, updated in June 2025) describes fragmented subpopulations in KwaZulu-Natal and Mpumalanga, extending marginally into Eswatini and Mozambique, with an extent of occurrence of about 3,900 km², an area of occupancy of about 200 km² and fewer than five locations;
  • the 2017 Biodiversity Management Plan places it in northern KwaZulu-Natal and in the Mananga area of eastern Mpumalanga, as well as in the adjacent parts of Mozambique and Swaziland;
  • The World List of Cycads gives Eswatini, Mozambique and South Africa (KwaZulu-Natal), and Species+ Eswatini, Mozambique and South Africa.

The species grows on the slopes of high ridges and on the cliffs lining the valleys, in full sun (PlantZAfrica), in grassland and savanna, on large rocky outcrops with scattered bush and on gorge cliffs, with a preference for deep, fertile soils (SANBI, 2023). One of its main vegetation types, Lebombo Summit Sourveld, is on South Africa’s national list of threatened ecosystems. Summers are hot, with 625 to 750 mm of rain a year, and winters cool, often foggy and misty (PlantZAfrica, after Whitelock, 2002).

Each plant bears on average one to three cones every three years. Pollination is effective, with more than 70% of the seeds tested being fertilised, and seedlings are abundant under the mother plants, but young plants 5 to 15 cm across are rare, perhaps because of fire, grazing or collection (SANBI, 2023). According to provincial reports, baboons, vervet monkeys, squirrels, hyraxes and crowned hornbills disperse the seeds in Mpumalanga, but recent observations show most seedlings within a metre of the adults.

Conservation status and regulation

Encephalartos lebomboensis is listed as Endangered (EN) on the IUCN Red List, under criteria A2acd; B1ab(ii,iii,v)+2ab(ii,iii,v), which combine a population decline with a small, fragmented and shrinking range. The assessment, by J.D. Bösenberg, is dated 19 May 2020 and was published in 2022 (The World List of Cycads, GBIF, Crossref). PlantZAfrica, in a text of 2003, called it Critically Endangered, especially the Mananga form, after a “Rare to Vulnerable” listing in 1996; that is not the category of the current IUCN assessment. Encephalartos senticosus is listed as Vulnerable (VU A2acd).

The figures available:

  • the IUCN cycad action plan (Donaldson, 2003) already listed it as Endangered, with about 5,000 plants, a high rate of decline and over-collection and habitat destruction as threats; it cites it as a species “ravaged by cycad collectors”, for which a community nursery was set up at Mananga;
  • the 2017 management plan also estimated about 5,000 wild plants, while noting that no recent survey had been carried out in Mpumalanga or KwaZulu-Natal;
  • SANBI (2023) keeps the figure of about 5,000: an aerial survey of KwaZulu-Natal counted 807 plants in one subpopulation in 2022, probably more than 1,000 in reality, and the largest Mpumalanga subpopulation, with 4,000 to 5,000 plants in 1984, may now hold only 1,000 to 3,000;
  • the decline exceeds 50% in 90 years, mainly through collection for gardens and landscaping; holes left by dug-up plants were still seen in recent surveys.

Further threats are the spread of farming and invasive plants (Lantana camara, Chromolaena odorata), which increase the risk of fire; the 2017 plan adds unconfirmed reports of increased harvesting of mature plants for the medicinal plant market.

The 2017 Biodiversity Management Plan (Government Gazette No. 40793) sets out the following actions for the species:

  • ground surveys in KwaZulu-Natal and Mpumalanga to establish the population size and the impact of poaching;
  • clearing of Lantana and Chromolaena on the Lebombo at Mananga;
  • surveys in the protected areas managed by SANParks, to find out whether the species occurs there;
  • an in situ genebank, with 2,000 seeds planted at ranger outposts at Mananga, and the reinforcement of the Piet Retief subpopulations with 1,000 seeds; a genebank planted near Piet Retief, within the historical range, is already producing cones.

The plan adds that viable ex situ collections exist in the national botanical gardens, which have already given seed to the Mpumalanga conservation agency and to the Mananga community nursery. That nursery, organised by the Mpumalanga agency in the late 1990s, put about 180,000 plants on the market in nearly nine years (SANBI, 2023).

Regulation, according to Species+ (consulted through its public API on 26 October 2026) and SANBI:

  • CITES: Appendix I since 4 February 1977, like the whole genus;
  • European Union: Annex A, current list in Regulation (EU) 2026/1383; for artificially propagated plants from South Africa, the EU has kept a negative opinion since 7 February 2013; the trade suspensions that applied to Mozambique (EU from 2008 to 2017, CITES from 2012 to 2018) are no longer in force, and a new consultation covering the whole genus has been open since 16 September 2026;
  • South Africa: collection of wild cycads banned (Government Notice No. 371 of 2012).

These notes do not replace the official texts: check Species+ and EUR-Lex before any purchase or import, and ask for documents proving that a plant was propagated in cultivation.

Growing Encephalartos lebomboensis

PlantZAfrica presents Encephalartos lebomboensis as one of the most popular cycads in cultivation: easy, hardy in full sun or light shade, relatively fast-growing and easy to transplant, needing excellent drainage and suited to tropical and warm temperate regions. According to SANBI (2023), cultivated plants can exceed 40 cm in ten years, depending on feeding; the document does not say whether this is height or diameter. Both forms, Mananga and Piet Retief, are common in South African nurseries (PlantZAfrica, management plan of 2017); in Europe and North America, many plants sold under this name may be Encephalartos senticosus.

Outdoor and in-ground cultivation

Jungle Music writes, on an undated page, that the species takes sun on the coast and inland in southern California, needs partial sun or filtered light in desert climates, a soil that drains well and preferably slightly acidic, and should be kept away from paths and seating because of its spines; the nursery calls it a good grower in the ground. In south-east France, a grower reported on the Fous de palmiers forum in October 2012 that a fine Encephalartos lebomboensis had been growing in the ground for several years at the Domaine du Rayol, on the Var coast, on a sunny bank in free-draining soil by the sea (photograph below). The species is also grown at the botanical garden of Nice (photograph above). In Brittany, members of the same forum mention trials at the exotic garden of Roscoff (2012) and a plant labelled Encephalartos lebomboensis seen there in February 2015; no growth or cold data were published.

Encephalartos lebomboensis
Encephalartos lebomboensis grown in the ground at the Domaine du Rayol, on the Var coast in south-east France.

Container cultivation

Where frosts are heavy, the species is best kept in a large pot, with the excellent drainage that PlantZAfrica requires, in full sun or light shade, and protected from heavy frost in winter; its suckers and clumping habit eventually call for a wide container. In Italy, the Naples Botanical Garden held four specimens in 1993–94 (Gaudio and colleagues, 1997), and the Messina Botanical Garden listed both Encephalartos lebomboensis and Encephalartos senticosus in 2009.

In cultivation in the UK, US and Australia

In Britain, the Royal Botanic Gardens, Kew, the Royal Botanic Garden Edinburgh and the National Botanic Garden of Wales declare the species to BGCI PlantSearch; a blog post of the Edinburgh garden shows Encephalartos lebomboensis in its former Orchids and Cycads House, whose public glasshouses are now closed for restoration as part of the Edinburgh Biomes project. In the United States, Montgomery Botanical Center in Coral Gables, Florida, holds six accessions in its online catalogue; the Huntington, Ganna Walska Lotusland, Descanso Gardens, the Los Angeles County Arboretum, the San Diego Botanic Garden, the San Diego Zoo, the University of California Botanical Garden at Berkeley, the US Botanic Garden in Washington, the Denver Botanic Gardens and several Hawaiian gardens (Honolulu, the National Tropical Botanical Garden, the University of Hawaii at Hilo) declare it to BGCI. Jungle Music reports that it usually has a hundred or more plants in stock, at modest prices for an Encephalartos. In Australia, the Royal Botanic Garden Sydney, the Royal Botanic Gardens Victoria and the System Garden of the University of Melbourne, the Botanic Garden of South Australia in Adelaide and James Cook University in Townsville declare it to BGCI. A BGCI listing shows that a garden has declared the species at some point, not that a plant is alive today, and, given the history of the name, some of these plants may be Encephalartos senticosus.

Propagation

Encephalartos lebomboensis is propagated from seed or from its suckers, which transplant readily (PlantZAfrica). To obtain seed, a female cone must be pollinated with pollen from a male of the same species at the right stage; in a garden where other Encephalartos cone, the risk of hybridisation is real. In the wild, more than 70% of seeds are fertilised and seedlings often come up around the mother plant (SANBI, 2023); in Captain Keith’s garden, the same happened in 1947 (Dyer, 1965). The seeds, with their scarlet fleshy coat, are poisonous: wear gloves to clean them. Seeds, like plants, fall under CITES Appendix I.

Pests and diseases

For pests, PlantZAfrica refers to the cycads of southern Africa in general: caterpillars and aphids on the leaves, weevils on the cones, beetle larvae in the stems, ants and termites on the roots. In cultivation in temperate climates, the main risk remains rot of the roots and trunk in cold, wet soil.

Cold hardiness

PlantZAfrica states that Encephalartos lebomboensis withstands light frost but may be damaged by heavy frost; its habitat has cool, misty winters. Dated reports with measured temperatures are lacking everywhere, and the confusion with Encephalartos senticosus makes the identity of many cultivated plants uncertain. As with all Encephalartos, survivals in cold areas often concern young plants whose caudex is still underground, protected by the thermal inertia of the soil; an adult with an aerial trunk has no such protection.

Mediterranean and European experience

At the Domaine du Rayol, on the coast of the Var, a plant has grown in the ground for several years (Fous de palmiers forum, 2012), without any published temperature record; the botanical garden of Nice also grows the species. These Mediterranean coastal gardens, where frost is light and short, give an idea of what can be expected in comparable climates, such as coastal California or southern Australia, but no minimum temperature is attached to them. In Brittany, the exotic garden of Roscoff, in Finistère, grows a plant labelled under this name (2015). The Jardin zoologique tropical at La Londe-les-Maures has published no observation on this species.

United Kingdom, United States and Australia

No dated cold report has been published from these countries, and no botanical source gives a USDA zone for the species; the zone ratings found on some websites cite no measurement. In Japan, a nursery reported in a sales article of July 2022 that a very large plant, with a 45 cm caudex, had spent the whole winter outdoors in the rain at its previous owner’s, with minimums of −7 °C (19.4 °F); neither the place nor the year is given, and the identity of the plant cannot be checked. In Britain, the safe course is a cool, bright glasshouse; outdoors, only the mildest coastal gardens could be considered, with excellent drainage and no guarantee.

Toxicity and precautions

No toxicity study specific to Encephalartos lebomboensis is documented, but the risk is documented in the genus: the toxicity of Encephalartos horridus was demonstrated as early as 1944 (Van der Walt), and Encephalartos contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a toxin of the liver and the nervous system; the seeds are the most dangerous part. The ASPCA reports vomiting, diarrhoea, liver damage and deaths in dogs, cats and horses that have eaten cycads.

Treat the species as poisonous: wear gloves to handle seeds, and keep plants and seeds out of reach of children and pets. If any part is swallowed, contact a poison centre, a doctor or a vet without delay.

Traditional uses

The species is harvested for traditional medicine: fragments of Encephalartos lebomboensis have been identified by DNA barcoding among the products sold at the Faraday traditional medicine market in Gauteng (Williamson and colleagues, 2016, cited by SANBI, 2023). SANBI notes that harvesters do not distinguish between cycad species. Lehmann (1834) reports, for the southern African Encephalartos as a whole, that bread was made from their pith; no published source describes this use for this species in particular.

Frequently asked questions

How can I tell Encephalartos lebomboensis from Encephalartos senticosus?

By the cones. In Encephalartos lebomboensis they are usually solitary, the males without a distinct stalk and with scales raised into a pyramid; in Encephalartos senticosus they come in groups of three or four, the males on a stalk and with drooping beaked scales. The leaves are not enough.

Is my “lebomboensis” really Encephalartos lebomboensis?

Not necessarily. Until 1996 all the cycads of the Lebombo bore this name, and the thousands of plants moved before the Jozini dam was built, widely distributed, are now Encephalartos senticosus. Only the cones or a documented origin can settle it.

Is Encephalartos lebomboensis frost-hardy?

Only to light frost. PlantZAfrica says it withstands light frost but may be damaged by heavy frost, and no measured minimum has been published. It grows in the ground on the French Mediterranean coast; elsewhere a pot brought in for the winter is safer.

Does Encephalartos lebomboensis grow fast?

Yes, for an Encephalartos. PlantZAfrica calls it relatively fast-growing, and SANBI notes that cultivated plants can exceed 40 cm in ten years.

How many trunks can it form?

Up to eight. It produces many suckers at the base, sometimes on the trunk, and forms large clumps over time.

Is Encephalartos lebomboensis endangered?

Yes, it is listed as Endangered. The wild population, estimated at about 5,000 plants, has lost at least half of its numbers, mainly through collection, and South Africa has included it in a national management plan.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Verdoorn, I.C. (1949). Encephalartos lebomboensis. The Flowering Plants of Africa 27: plates 1078–1079. [Original description.]
  • Henderson, M.R. (1945). [Revision of Encephalartos transvenosus and “West’s Cycad”.] Journal of South African Botany 11(1). [Cited by Verdoorn (1949).]
  • Dyer, R.A. (1965). The cycads of southern Africa. Bothalia 8: 405–515. [Description, distribution in the broad sense, distinction from Encephalartos natalensis, hybrids with Encephalartos villosus, Jozini dam, seedlings in Keith’s garden.]
  • Palmer, E. & Pitman, N. (1972). Trees of Southern Africa. Balkema, Cape Town. [Zulu name, quoted by The Gymnosperm Database.]
  • Osborne, R. (1988). Focus on Encephalartos lebomboensis. Encephalartos 15: 6–15. [Members-only journal of the Cycad Society of South Africa; cited by SANBI and The World List of Cycads.]
  • Vorster, P. (1995). The identity of Encephalartos lebomboensis. In: Vorster, P. (ed.), Proceedings of the Third International Conference on Cycad Biology: 245–254. Cycad Society of South Africa, Stellenbosch. [Cited by Vorster (1996).]
  • Vorster, P. (1996). Encephalartos senticosus (Zamiaceae): a new species from northern KwaZulu-Natal and Swaziland. South African Journal of Botany 62(2): 76–79.
  • Whitelock, L.M. (2002). The Cycads. Timber Press, Portland. [Climate of the habitat, cited by PlantZAfrica.]
  • Donaldson, J.S. (ed.) (2003). Cycads. Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group, Gland and Cambridge. [Status table, Mananga community nursery.]
  • Department of Environmental Affairs (2017). Biodiversity Management Plan for 11 critically endangered and four endangered Encephalartos cycad species. Government Gazette No. 40793 (21 April 2017). [§ 4.13 on Encephalartos lebomboensis.]
  • Williamson, J. et al. (2016). [DNA barcoding of cycads sold in traditional medicine markets.] [Cited by SANBI (2023).]
  • Van der Walt, S.J. (1944). Recent investigations into the toxicity of plants, etc., in the Union of South Africa. Onderstepoort Journal of Veterinary Science and Animal Industry 20(1). [Toxicity of Encephalartos horridus, genus-level data.]
  • Bösenberg, J.D. (2022). Encephalartos lebomboensis. The IUCN Red List of Threatened Species 2022: e.T41907A51049248. [Assessment cited by The World List of Cycads, SANBI and Crossref.]
  • Haynes, J.L. (2022). Etymological compendium of cycad names. Phytotaxa 550(1): 1–31. https://doi.org/10.11646/phytotaxa.550.1.1 [Etymology, cited by The World List of Cycads.]
  • Calonje, M., Stevenson, D.W. & Osborne, R. (2026). The World List of Cycads, version 2026.08.15. Montgomery Botanical Center, Coral Gables. https://doi.org/10.5281/zenodo.21958524 [Checklist.]