Kei cycad (Encephalartos princeps)

KingdomPlantae
PhylumTracheophyta
ClassCycadopsida
OrderCycadales
FamilyZamiaceae
GenusEncephalartos (1)
SizeHeight: up to 5 m (2)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix I of CITES (3).

Having remained relatively unchanged for millions of years, the cycads are often referred to as ‘living fossils’ (4) (5). The Kei cycad is a medium to large cycad, distinguished from other Encephalartos species within its range by its closely crowded and overlapping, bluish-green leaflets (6) (7). Although woody in appearance, like all cycads, the stems are mostly comprised of soft, pithy storage tissue protected by a solid layer of old leaf bases (6) (8). The reproductive organs of cycads take the form of cones, similar in appearance to those of a conifer (5), with each Kei cycad stem producing one to three cones (6). As with all cycads, the male and female cones of this species, both of which are olive-green (2), are borne on separate plants (8).

The Kei cycad occurs in the catchment of the Kei River in the Eastern Cape, South Africa (1) (2) (6).

Found on rocky slopes and ridges in arid low succulent shrubland (1).

Cycads are long-lived, slow growing plants that always occur as individual male or female plants (6) (8). There is no way of determining the sex of a cycad until it begins to produce its first cone (8). For a long time cycads were thought, like cone-producing conifers, to be entirely wind pollinated (9). However, studies now suggest that the vast majority, if not all cycads, are actually pollinated by insects or more specifically weevils (6) (8) (9). To attract pollinators, male and female cones produce powerful odours, usually in the early morning or evening (8). Travelling between the sexes, the weevils pollinate the plants by inadvertently transferring pollen from the male cones to the receptive ovules of the female cones (8) (10).

The seeds produced by cycads are large and have a fleshy outer coat, but are relatively short-lived and vulnerable to desiccation. The fleshy outer layer is desirable to a range of animals such as birds, rodents and bats, depending on the species of cycad and region it occupies. However, with any luck the unpalatable seed is discarded some distance away from the parent plant in a hospitable environment in which to germinate (6).

Like many other South Africa cycad species, the Kei cycad is threatened by habitat loss, over-collection, and the spread of alien vegetation (4).

There are not known to be any specific conservation measures in place for the Kei cycad, but it is listed on Appendix I of CITES, which permits trade only under exceptional circumstances (3).

For further information on the conservation of cycads in South Africa see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (October, 2009)
    http://www.iucnredlist.org/
  2. Carruthers, V. (2005) The Wildlife of Southern Africa: A Field Guide to the Animals and Plants of the Region. Struik, Cape Town.
  3. CITES (October, 2009)
    http://www.cites.org
  4. Donaldson, J.S. (2003) Cycads, status survey and conservation action plan. IUCN/SSC-Cycad Specialist Group. IUCN, Gland, Switzerland.
  5. Royal Botanic Gardens, Kew (October, 2009)
    http://www.kew.org/plants/cycads/index.html
  6. The Cycad Pages (October, 2009)
    http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/index.html
  7. Palm and Cycad Societies of Australia (PACSOA) (October, 2009)
    http://www.pacsoa.org.au/cycads/Encephalartos/princeps.html
  8. Whitelock, L.M. (2002) The Cycads. Timber Press, Portland, Oregon.
  9. Jolivet, P. (2005) Cycads and beetles: recent views on pollination. The Cycad Newsletter, 28: 3 - 7.
  10. Donaldson, J.S. (1997) Is there a floral parasite mutualism in cycad pollination? The pollination biology of Encephalartos villosus (Zamiaceae). American Journal of Botany, 84: 1398 - 1406.