Encephalartos friderici-guilielmi

Encephalartos friderici-guilielmi

Encephalartos friderici-guilielmi is a stout, woolly-crowned cycad of South Africa that grows on mountains and rocky slopes in the interior of the Eastern Cape, around Queenstown and Cathcart, and eastwards towards Kokstad. This species of the genus Encephalartos, described in 1834 by Johann Georg Christian Lehmann, has stiff blue-green leaves with narrow, crowded leaflets, a crown covered in brown wool and more cones than any other member of the genus. For much of the twentieth century it was confused with Encephalartos cycadifolius, the name under which it still appears in older books. Its habitat is dry in winter and has frost and sometimes snow, and European growers count it among the hardiest species of the genus, provided drainage is perfect. It is listed as Near Threatened by the IUCN.

Key facts about Encephalartos friderici-guilielmi

  • Accepted name: Encephalartos friderici-guilielmi Lehm. (1834), accepted by The World List of Cycads (version 2026.08.15), GBIF and Species+
  • Former names and synonyms: Encephalartos cycadifolius var. friderici-guilielmi (Lehm.) Regel (1874), Encephalartos acanthus Mast. (1878); long misapplied name: Encephalartos cycadifolius
  • Family: Zamiaceae, order Cycadales
  • Common names: white-haired cycad (English, PlantZAfrica and Species+)
  • Natural range: South Africa, interior of the Eastern Cape (Queenstown and Cathcart districts, former Transkei), east to the Kokstad area (KwaZulu-Natal)
  • IUCN status: Near Threatened (NT, criteria A2ac+4ac), 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; positive EU opinion for artificially propagated plants from South Africa up to a caudex diameter of 15 cm
  • Documented hardiness: in France, young plants in the ground unharmed at −8 °C (17.6 °F) and at −9.5 to −10 °C (14.9 to 14 °F) in February 2012; losses from excess wet or long frosts; killed outdoors at −15.6 to −12.8 °C (4 to 9 °F) in North Carolina in the winter of 2013–2014 (see Cold hardiness)
  • Light and soil: full sun, very free-draining soil, little water (PlantZAfrica)
  • Habit and adult size: trunk 35 to 60 cm in diameter, rarely up to 4 m tall, eventually leaning and lying down; up to six stems; leaves 1 to 1.5 m long
  • In the UK, US and Australia: Lotusland, the Huntington, San Diego and a dozen other US gardens; Royal Botanic Gardens Victoria (outdoors in Melbourne) and Adelaide; no British garden declares it to BGCI
  • Toxicity: treat seeds and tissues as poisonous, as in other Encephalartos (see Toxicity and precautions)

How to recognise Encephalartos friderici-guilielmi

Look for an open crown covered in brown wool, massive trunks and stiff leaves with narrow, entire, very crowded leaflets, often bluish or silvery when young. Dyer (1965) describes it as follows, with additions from PlantZAfrica:

  • Trunk: single or branching at the base (up to six stems in old plants, which sucker freely), stout, 35 to 60 cm in diameter, rarely up to 4 m tall, eventually leaning and then lying down, with the crown turning upwards
  • Leaves: 1 to 1.5 m long (Dyer: 1 to 1.2 m), fairly stiff, straight or arching, spreading below the crown when the plant is in cone
  • Leaflets: bluish or silvery when young, yellowing with age, crowded and overlapping in the upper half of the leaf; median leaflets 10 to 17 cm long (10 to 18 cm according to PlantZAfrica) and about 7 mm wide, with seven to nine raised veins beneath, without teeth, ending in a point
  • Cones: three to several together, up to ten on large male plants (twelve according to PlantZAfrica, which gives up to six female cones), covered in greyish-yellow to brownish wool; male cones 20 to 30 cm by 6 to 7 cm (20 to 40 cm by 6 to 10 cm according to PlantZAfrica); female cones barrel-shaped, 25 to 30 cm by 15 to 17 cm (up to 20 cm across according to PlantZAfrica), remaining on the plant for more than six months before breaking up
  • Seeds: pale yellow to orange-yellow, about 3 by 2 cm

PlantZAfrica (J. Winter, Kirstenbosch National Botanical Garden, August 2006) notes that it bears the largest number of cones in the genus, that the leaves are blue-green and darken with age, and that the crown is covered in loose brown hair, especially when new leaves and cones emerge. Lehmann’s original description (1834) already stressed the wheat-coloured wool covering the trunk, the leaf bases and the cones, and the hundred to hundred and twenty pairs of leaflets, hairy beneath when young.

Encephalartos friderici-guilielmi
Encephalartos friderici-guilielmi grown at the botanic garden of Nice, France.

Hybrids

No natural hybrid of Encephalartos friderici-guilielmi has been described. Dyer (1965) notes that at the lowest altitudes, near the confluence of the White Kei and Black Kei rivers, Galpin found it growing with Encephalartos princeps, and quotes Chamberlain (1919), who stressed its strong variation from one locality to another and the risk of confusing it with a related species sometimes growing alongside. In cultivation, as with other Encephalartos, crosses are possible when several species cone together: a plant raised from seed collected in a garden is not necessarily pure.

Possible confusion

The historical confusion is with Encephalartos cycadifolius, a smaller species of the Bedford and Cradock mountains further west. According to Dyer (1965), Encephalartos cycadifolius has a trunk with almost no wool at the top, shorter (9 to 13 cm) and narrower (4 to 5 mm) median leaflets with five or six veins and slightly rolled margins, and only one or two cones per stem, against three to ten in Encephalartos friderici-guilielmi.

Encephalartos ghellinckii, from the Drakensberg, belongs to the same group of woolly-coned species, but its very narrow leaflets (2 to 4 mm) have clearly rolled margins. Encephalartos lanatus, described from the former Transvaal, also has fine leaflets and woolly cones but lives much further north. Beginners sometimes compare Encephalartos friderici-guilielmi with the sago palm, Cycas revoluta: the latter carries its seeds in a loose cluster rather than in compact, woolly cones, as Dyer (1965) points out in connection with Encephalartos ghellinckii.

Taxonomy

Encephalartos friderici-guilielmi is accepted by The World List of Cycads, GBIF and Species+. Lehmann published it on 15 March 1834 in the Allgemeine Gartenzeitung (volume 2, no. 11, p. 84), then in the sixth part of his Novarum et minus cognitarum stirpium pugillus (p. 8, plates 1 to 3), where he established the genus Encephalartos; The World List of Cycads treats these plates as the probable lectotype. According to PlantZAfrica, the description was based on material collected by Ecklon and Zeyher.

The name was then eclipsed. Regel reduced it in 1874 to a variety of Encephalartos cycadifolius, and Masters described an Encephalartos acanthus in 1878, now a synonym (The World List of Cycads). For half a century the Queenstown and Cathcart plants were called Encephalartos cycadifolius, for instance in the Flora Capensis of 1933. In 1965 R. Allen Dyer, director of the Botanical Research Institute (now part of SANBI), restored the name Encephalartos friderici-guilielmi for these populations (Journal of South African Botany 31: 116); as a result the name Encephalartos eximius, coined in the meantime for the true Encephalartos cycadifolius, became superfluous. A typification note by P. J. Vorster (2004, Bothalia 34) is cited by The World List of Cycads.

Etymology and history

The epithet honours Frederick William III (1770–1840), King of Prussia and patron of science, whose palm house on Peacock Island (Pfaueninsel), near Potsdam, was unrivalled at the time (Haynes, 2022, via The World List of Cycads). Lehmann says so himself: regarding the species as the most beautiful of all cycads, he wished to adorn it with the name of the monarch who had built “the finest of homes for palms” on Peacock Island.

Lehmann (1834) relates that the trunks imported into Europe had lost almost all their wool in a fire that had swept, a few years earlier, through the thickets where they were dug up. He gives the measurements taken by Ecklon and Zeyher: trunks four to five feet tall and one to one and a quarter feet in diameter, producing twenty to twenty-five leaves a year. A century later, the confusion with Encephalartos cycadifolius clouded the history of the species until Dyer’s revision (1965), which also found it sturdier and easier to grow than Encephalartos cycadifolius.

Common names

PlantZAfrica and Species+ give the English name white-haired cycad, which refers to the pale wool of the crown and cones; PlantZAfrica also lists the species as number 4 in South Africa’s national list of trees. No Xhosa or Afrikaans name specific to the species is attested in a verifiable source.

In the wild

Encephalartos friderici-guilielmi grows in large numbers on the mountains and rocky slopes of the Queenstown and Cathcart districts, in the interior of the Eastern Cape, and extends in places eastwards to the Kokstad area (Dyer, 1965; PlantZAfrica). Dyer considered the more westerly records in the literature “almost certainly erroneous”; he also illustrates plants near Tsolo, in the former Transkei. The World List of Cycads gives the Eastern Cape and KwaZulu-Natal.

The species lives in grassland and among other low vegetation, in a climate that is very hot in summer and very cold in winter, with frost and snow; rain falls in summer, 375 to 500 mm a year, and PlantZAfrica concludes that the species suits other relatively dry climates with winter frost. Fire regularly sweeps these grasslands: adult plants withstand severe scorching and only the leaf stalks burn, but young plants not sheltered by rocks are vulnerable, and adults grow mostly among rocks, which protected them when young. As in other cycads, pollination involves wind and insects (PlantZAfrica).

Conservation status and regulation

Encephalartos friderici-guilielmi is listed as Near Threatened (NT) on the IUCN Red List under criteria A2ac+4ac, which concern a past and ongoing population reduction. The assessment by J. D. Bösenberg is dated 26 May 2020 and was published in 2022 (The World List of Cycads, GBIF, Crossref).

The IUCN cycad action plan (Donaldson, 2003) already classed it as Near Threatened, with 5,000 to 10,000 plants, a slight decline, over-collecting as the main threat and little loss of habitat; it cites the Tsolo population, in the Eastern Cape, as an example of a marked decline caused by bark stripping for traditional medicine.

Like all species of the genus, it has been listed in CITES Appendix I since 4 February 1977 and, in the European Union, in Annex A of the wildlife trade regulations (current list: Regulation (EU) 2026/1383), according to Species+. For artificially propagated plants from South Africa, the EU Scientific Review Group has held a positive opinion since 20 June 2011, limited to plants with a caudex no more than 15 cm in diameter; a new consultation covering the whole genus opened on 16 September 2026. Check the current rules and ask for proof of cultivated origin before any purchase.

Growing Encephalartos friderici-guilielmi

PlantZAfrica describes a vigorous, easily grown species that develops a stout stem and adapts well to different climates: it even thrives at Kirstenbosch, in Cape Town, a frost-free and wet region. It needs full sun and excellent drainage, does poorly in shade and suits a rockery among low succulents. It is water-wise and needs no heavy watering; high-pressure irrigation damages its leaves and stems. PlantZAfrica recommends well-rotted compost in autumn and, in early spring, two handfuls per plant of a mixture of bone meal, organic fertiliser and a balanced inorganic fertiliser. Dyer (1965) found it sturdier and easier to grow than Encephalartos cycadifolius.

Outdoor and in-ground cultivation

Growth is slow but variable. In France, a grower near Nantes saw his plant, in the ground since 2004, produce larger leaves each year in May or June, even during the cool summer of 2007. Several members of the Fous de palmiers forum stress drainage and the risk of rot in plants received bare-root or set in heavy compost. In the Tarn, a grower found in 2012 that the caudex of a plant set in full sun had been scorched, and advises burying it slightly. In Agen, two in-ground trials failed through excess wet (2011). The photograph above shows a plant grown at the botanic garden of Nice, on the Riviera. For readers in comparable Mediterranean climates (California, southern Australia), these accounts point to a sunny, very free-draining site where the soil stays dry in winter.

Container cultivation

PlantZAfrica recommends the species as a container plant as well as a feature plant in full sun. On the Italian Tropicamente forum, a grower in Ravenna who kept it in a pot, slightly sheltered from winter rain, reported in December 2008 that his plant produced three to four leaves a year and that its caudex had almost doubled in three years; in November 2009 the plant, bought six years earlier with a caudex 8 cm in circumference, had eighteen leaves and a circumference of 31 cm. It died after the frost of December 2009 (see Cold hardiness), a reminder that roots in a pot are more exposed to cold than in the ground. Another Italian grower, without giving his locality, found the species more like an ornament than a plant: a large specimen of his had grown only four times in ten years before dying (December 2008).

In cultivation in the UK, US and Australia

In the United States, Ganna Walska Lotusland in Montecito names Encephalartos friderici-guilielmi among the notable species of its cycad garden, which is planted outdoors. The Huntington, the San Diego Botanic Garden, the San Diego Zoo, the University of California Botanical Garden at Berkeley, the Gardens of Golden Gate Park, the Arboretum at Cal State Fullerton, the Missouri Botanical Garden, the Atlanta Botanical Garden, Denver Botanic Gardens, Norfolk Botanical Garden, Moore Farms Botanical Garden, Honolulu Botanical Gardens and the University of Hawaii at Hilo’s garden declare it to BGCI PlantSearch, which shows that a garden has declared the species at some point, not that a plant is alive today. Montgomery Botanical Center’s online catalogue does not list it. In Australia, the Royal Botanic Gardens Victoria grows it in outdoor beds at Melbourne Gardens, according to its living collection census, and the Botanic Garden of South Australia in Adelaide declares it to BGCI. No British garden lists it in BGCI PlantSearch. In Italy, the Naples Botanic Garden held two plants of South African origin in 1993–1994 (Delpinoa, 1997), and the Messina botanic garden listed the species in 2009.

Encephalartos friderici-guilielmi
Encephalartos friderici-guilielmi grown in the ground outdoors.

Propagation

Encephalartos friderici-guilielmi is propagated from seed or by removing well-developed suckers (PlantZAfrica). PlantZAfrica gives the method:

  • to obtain seed true to type, hand-pollinate the female cone with pollen from a male cone of the same species
  • sow in spring on clean, coarse sand with bottom heat of 25 to 28 °C (77 to 82.4 °F); germination is slow and can be spread over a year, the radicle appearing first, then the leaves
  • after about ten months, pot the seedlings into 3-litre sleeves of free-draining compost and water sparingly until the first signs of growth
  • remove suckers about 25 cm in diameter in early spring, after cutting off all their leaves; let the wound dry, root them in clean sand, then plant them out

Seeds and plants fall under CITES Appendix I.

Pests and diseases

PlantZAfrica names scale insects and mealybugs, on the underside of the leaflets, caterpillars and snout beetles, which destroy the seed; a tiny gall midge can damage new leaves as they emerge, turning them black, and it recommends spraying the crown with a contact insecticide every two weeks while new leaves appear. In cultivation the main risk remains trunk and root rot in wet soil: a grower in Agen reports on the Fous de palmiers forum that he lost two plants in the ground “through too much wet” (2011), and another lost one in a glasshouse kept at 4 to 5 °C (39.2 to 41 °F).

Cold hardiness

Encephalartos friderici-guilielmi has a reputation as one of the hardiest species in the genus: its habitat has frost and snow (PlantZAfrica), and the dated reports from Europe agree, provided the soil is dry in winter. It is not invulnerable: long frosts and wet have killed plants, and it did not survive the winter of 2013–2014 in North Carolina. As with all Encephalartos, survival in the cold often concerns young plants whose caudex is still underground, protected by the thermal inertia of the soil, sometimes by snow; most of the reports below concern small plants, and an adult with an aerial trunk has no such protection.

Mediterranean and European experience

  • A grower in the Nantes vineyards (Vallet, Loire-Atlantique, western France) reports on the Fous de palmiers forum that his plant, in the ground since 2004, came through −8 °C (17.6 °F) in January 2007 without protection or damage; in February 2012 he recorded −9.5 °C (14.9 °F), again without damage, and confirmed in October 2012 that it showed no after-effects, judging it “hardier than Cycas revoluta” in his garden.
  • A grower in the Béarn (south-western France) reports that a small plant (4 cm caudex, three leaves), in the ground without protection, came through its first winter and the start of the 2010–2011 winter intact with lows of −6 to −7 °C (21.2 to 19.4 °F); in February 2012 it took repeated frosts down to −10 °C (14 °F) with no visible damage and showed no after-effects in October 2012.
  • On the Côte Bleue (Bouches-du-Rhône, near Marseille), a grower found a plant in the ground for a year in good shape in February 2010, despite −7 °C (19.4 °F) under shelter and a long, snowy winter. After the February 2012 cold spell, almost a week of near-continuous frost, the crown of his largest plant, kept dry, was scorched, while the oldest kept a few green leaflets. In his former garden near Paris, the same cold spell killed a small plant (3 to 4 cm caudex) and defoliated a large one (13 to 15 cm), which he put back in a pot.
  • In the Tarn, near Toulouse, a grower reported in August 2026 that a plant in the ground had come through −9 °C (15.8 °F) the previous winter.
  • In Ravenna (Emilia-Romagna, Italy), a grower reports on the Tropicamente forum that his potted plant, slightly sheltered from rain, had no scorch in earlier winters with lows of −3 °C (26.6 °F) (December 2008), but that in December 2009 it took snow and hoar frost at −7 °C (19.4 °F) under a terrace near a wall (−10 °C, 14 °F, in the open, with a daytime high of −3 °C): it lost its leaves, the trunk seemed sound in April 2010, and he confirmed in 2013 that the plant had died from that frost.

For readers in comparable climates, from the Riviera to coastal California and southern Australia, these reports suggest that young plants in a dry, sunny site can take brief frosts of −8 to −10 °C, while pot culture and prolonged wet frost are the main dangers.

United Kingdom, United States and Australia

In Raleigh, North Carolina, the Juniper Level Botanic Garden listed Encephalartos friderici-guilielmi among the cycads that did not survive outdoors, unprotected and unmulched, in the winter of 2013–2014, when its lows were between 4 and 9 °F (−15.6 to −12.8 °C) depending on the site (article of 7 August 2014). In Melbourne, the Royal Botanic Gardens Victoria grows it in outdoor beds, and Lotusland, in Montecito, grows it in its outdoor cycad garden, but neither publishes cold data. No USDA zone is published for the species by a botanical source. In Britain, where botanic gardens keep their cycads under glass, no outdoor trial is documented.

Toxicity and precautions

No toxicity study specific to Encephalartos friderici-guilielmi 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, like other cycads, contain toxic glycosides (cycasin, macrozamin), from which methylazoxymethanol is derived, a toxin affecting 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 away from children and pets. If any part is swallowed, contact a poison centre, a doctor or a vet without delay.

Traditional uses

The main documented use is the stripping of bark from the trunks for traditional medicine and magic, which caused a marked decline of the Tsolo population, in the Eastern Cape (Donaldson, 2003). Lehmann (1834) reports, for the southern African Encephalartos as a whole, that local people roasted the pith of the trunks to eat it; no published source describes this use for this species in particular.

Frequently asked questions

Is Encephalartos friderici-guilielmi frost-hardy?

Yes, it is one of the hardiest Encephalartos, with reservations. Young plants in the ground have taken −8 to −10 °C (17.6 to 14 °F) without damage in western and south-western France; others have died after long frosts or from excess wet, and plants died outdoors in North Carolina at −15.6 to −12.8 °C (4 to 9 °F). Perfect drainage and a dry winter soil are essential.

Is it hardier than Cycas revoluta?

It depends on the garden. A grower near Nantes judged it hardier than Cycas revoluta after the 2012 cold spell, while another, near Marseille, found the two behaved similarly. No measured comparison has been published.

How can it be told from Encephalartos cycadifolius?

By the crown and the cones. Encephalartos friderici-guilielmi has a very woolly crown, longer and broader leaflets and three to ten cones per stem; Encephalartos cycadifolius has an almost bare apex and only one or two cones.

Why such a long name?

It honours Frederick William III, King of Prussia, whose palm house near Potsdam was the finest of its day. Lehmann dedicated to him in 1834 what he considered the most beautiful of the cycads.

Does it grow fast?

Slowly but steadily in sun and a well-drained soil. Growers see one to four leaves a year on young plants, sometimes more in a well-fed pot, and PlantZAfrica calls it a vigorous grower.

Can it be grown in a pot?

Yes, PlantZAfrica recommends it as a container plant. A pot makes it easy to keep dry in winter, but the roots are more exposed to cold: a potted plant died in Ravenna after the frost of December 2009.

Is it endangered?

It is Near Threatened. Its populations are declining mainly through collecting, including bark stripping for traditional medicine.

Further reading on Succulentes

Sources

Reference sites

Bibliography

  • Lehmann, J.G.C. (1834). Encephalartos friderici-guilielmi. Allgemeine Gartenzeitung 2(11): 84; and Novarum et minus cognitarum stirpium pugillus 6: 8, plates 1–3. Hamburg. [Original description.]
  • Chamberlain, C.J. (1919). The living cycads. University of Chicago Press, Chicago. [Remark on the variation of the species, after Dyer (1965).]
  • Dyer, R.A. (1965). The cycads of southern Africa. Bothalia 8: 405–515. [Description, distribution, distinction from Encephalartos cycadifolius and Encephalartos ghellinckii.]
  • Dyer, R.A. (1965). [Reinstatement of Encephalartos friderici-guilielmi]. Journal of South African Botany 31: 116. [Cited by Dyer (1965, Bothalia).]
  • Kemp, M. (1989). Focus on Encephalartos friderici-guilielmi. Encephalartos 18: 4–9. [Journal of the Cycad Society of South Africa, members only.]
  • Gaudio, L., Aceto, S., Caputo, P., Cozzolino, S., Siniscalco Gigliano, G., Moretti, A. & De Luca, P. (1997). Enzyme polymorphism in Encephalartos Lehmann (Zamiaceae). Delpinoa n.s. 35–36: 55–64. [Plants in Naples in 1993–1994; table 1.]
  • Donaldson, J.S. (ed.) (2003). Cycads. Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group, Gland and Cambridge. [Status table, bark stripping at Tsolo.]
  • Vorster, P.J. (2004). Typification of Encephalartos. Bothalia 34(2): 112–113. [Reference given by The World List of Cycads.]
  • 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.]
  • Bösenberg, J.D. (2022). Encephalartos friderici-guilielmi. The IUCN Red List of Threatened Species 2022: e.T41930A51054937. [Assessment cited by The World List of Cycads 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, via 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.]