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Encephalartos hildebrandtii
Zamiaceae FAMILY Near Threatened

Encephalartos hildebrandtii

Encephalartos hildebrandtii

Edibility
1/5
Medicinal
0/5

Safety & Hazards

Consumption of the seeds can lead to liver cancer[1]. We have no further specific information for this species, but most if not all members of this genus are believed to contain toxins. The two main toxic compounds that have been identified are cycasin and macrozamin. When ingested in sufficient quantities, these compounds are extremely poisonous to humans and many other animals, and have been shown to cause liver damage and cancer. Cycasin and macrozamin have a cumulative effect upon the body and are suspected of causing neurological disorders when ingested in small amounts over long periods of time. There is a long history of human use of this genus as a starch-rich food, but it should be noted that the plants needed to be treated in various ways in order to remove any toxic principles. Caution should be exercised even with properly prepared foods, since even then regular consumption may lead to severe health problems and death. Since many of these species are becoming increasingly rare in the wild, this is probably a food best left to times of food shortage when other, better foods, are not available[2, PFAF].

Cultivation Details

HabitEvergreen Tree
Growth—

Although Encephalartos hildebrandtii grows at or near sea level, and almost on the equator, it exhibits an unusual amount of cold tolerance and is able to survive in the warmest parts of the temperate zone as well. In the warmer portions of southern California, for example, it grows with apparent ease, only suffering defoliation or leaf burn during extreme winters[2]. An easily grown plant, happy in either full sun or shade, and adaptable to extremes of moisture[3]. An almost universal requirement for cycads is a well-drained but moisture-retentive soil, and by far the best soils are sandy gravels and light loams which provide the required drainage and aeration necessary for good growth. Cycads will generally not grow well in clay soils unless those soils are heavily amended with sand and organic matter[2]. A neutral soil (pH 7), is generally best for most species of cycads and allows the proper absorption of nutrients. A slightly acid soil is better for most cycads than a basic one[2]. The plant produces occasional suckers[3]. Cycad species can usually be transplanted easily even when quite large. The best time for moving them is just before the beginning of a new growing season, the roots being trimmed if they are damaged and perhaps some leaves being removed. New roots should develop quickly as the season progresses[2]. Species in this genus form structures known as coralloid roots. These roots branch off from the taproot or secondary roots and are distinctive in that they grow laterally or upward, forming a nodular mass at the apex. These coralloid roots occur slightly below or slightly above the soil surface and generally contain cyanobacteria, also known as blue-green algae. These are able to fix atmospheric nitrogen and make it available as a nutrient to the plant. The ability to extract this important nutrient from the air explains how many cycad species are able to survive on almost sterile soils[2]. A dioecious species, with individual plants producing either all male or all female cones. Therefore both male and female forms of the plant need to be grown if seed is required[2]. On very rare occasions, usually when a plant has been under severe stress, it can change sex and produce either all female or all male cones[2]. Encephalartos species always produce full-sized seeds, even if the cone has not been pollinated, in which case the resulting seed is not viable but appears normal in every other respect[2]

Propagation

Seeds - best sown as soon as they are ripe, though the seeds of many species will take a few months to finish maturing the embryo before they are ready to germinate. Sow the seeds in a tray in a freely-draining medium and place in moderate shade. Bottom heat at about 27°c will hasten seed germination dramatically. Young roots are quite brittle and once germination takes place, the root grows rapidly. It is important to pot up the seedlings at this time in order to give them enough root-space. Grow on the plants in pots until large enough to plant out[2]. Division of off-sets or suckers is best carried out just before the plant comes in to new growth at the start of the growing season[2]. Cite as: Tropical Plants Database, Ken Fern. tropical.theferns.info. 2026-02-20. <tropical.theferns.info/viewtropical.php?id=Encephalartos+hildebrandtii>

Pollinators

Insects

References

  1. [1]Edible Wild Plants of Tanzania — Ruffo, C.K.: Birnie, A. & Tengnas, B. · Regional Land Management Unit; Nairobi. · 2002 · ISBN 9966-896-60-0 ↩︎A very well presented, simple guide to growing and utilizing wild food plants in Tanzania, with line drawings of each plant, a description, habitat and range, non-food as well as food uses, plus basic information on growing the plants.
  2. [2]The Cycads — Whitelock L.M. · Timber Press; Portland, Oregon · 2002 · ISBN 0-88192-522-5 ↩︎An excellent book dealing with the eleven different genera and almost 300 species of plants we know as Cycads. There are detailed descriptions and a host of other information for each species.
  3. [3]Palm and Cycad Societies of Australia. — http://www.pacsoa.org.au/ ↩︎Contains at least a little information on the majority of palm and cycad species, plus a wealth of photographs. A first class website.
  4. [4]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  5. [5]Economic Botany of the Cycads — Thieret J.W. · 1958 · https://doi.org/10.1007/BF02863122 ↩︎
  6. [6]Cornucopia II — Facciola. S. · Kampong Publications, California. · 1998 · ISBN 0-9628087-2-5 ↩︎The second edition of an excellent guide to the edible uses of plants, though it does not give any details of cultivation etc.
  7. [7]The Cycad Pages — Royal Botanic Gardens, Sydney. · 2012 · http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/wlist.html ↩︎A website dedicated to the various species of Cycad, with a comprehensive description of all the known species (as of 2012). At present (2015), the site is still running but is no longer being updated
  8. [PFAF]Plants for a Future — pfaf.org ↩︎