Cycad (Encephalartos inopinus)

Description

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Cycad fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Cycad description

With a wild population estimated at less than 300 individual plants ^{(1) (4)}, Encephalartos inopinus is amongst South Africa’s growing number of endangered cycads ⁽²⁾. A highly distinctive species, E. inopinus has a spreading crown of silvery blue-green leaves, made up of widely spaced leaflets that droop gracefully away from the leaf stem. Individual plants may be single or multi-stemmed, and usually grow upright, or along the ground in the case of very old specimens, while on cliff sides, stems may be seen hanging pendulously, with just the crown turned upwards ^{(2) (5)}. Male plants bear up to four, pointed, silvery-green cones, while female plants bear one to three, bluish-green cones that become greenish-yellow at maturity ^{(2) (6)}.

Size

Height: up to 3 m ⁽²⁾

Cycad biology

Cycads are long-lived, slow growing plants that always occur as individual male or female plants ^{(7) (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 ^{(7) (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 ⁽⁷⁾.

Cycad range

Encephalartos inopinus is restricted to Mpumalanga in South Africa ^{(1) (6)}.

Cycad habitat

Encephalartos inopinus is found in thick bush, on steep slopes and rocky outcrops ^{(1) (2)}.

Cycad status

Encephalartos inopinus is classified as Critically Endangered (CR) on the IUCN Red List ⁽¹⁾ and listed on Appendix I of CITES ⁽³⁾.

Cycad threats

Over the past few decades, many South African cycads have become increasingly scarce in the wild, with many species now facing the very real threat of extinction. Various factors account for their decline, but the main threats include illegal harvesting for horticulture, food and medicine, habitat loss, and the spread of alien vegetation ⁽¹⁰⁾. Owing to its distinctive appearance, E. inopinus has suffered greatly from the activities of collectors, with the remaining plants now scattered sparsely over its restricted range ^{(2) (6)}.

Cycad conservation

There are not known to be any specific conservation measures in place for this Critically Endangered species, but like all South African cycads, E. inopinus is partially protected by its listing on Appendix I of CITES, which permits trade only under exceptional circumstances ⁽³⁾.

Find out more

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

• The Cycad Society of South Africa:
  http://www.cycadsociety.org/

• South African National Biodiversity Institute:
  http://www.sanbi.org/

• IUCN/SSC Cycad Specialist Group:
  http://www.cycadsg.org/

Authentication

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

Glossary

Germinate

The beginning of growth, usually following a period of dormancy and in response to favourable conditions. For example, the sprouting of a seedling from a seed.

Ovules

A structure within the female reproductive organs of plants that contains eggs and when fertilized by pollen, develops into seeds.

Pollinate

To transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Pollinators

Animals that in the act of visiting a plant's flowers transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

References

1. IUCN Red List (December, 2009)
   http://www.iucnredlist.org/
2. The Cycad Society of South Africa (December, 2009)
   http://www.cycadsociety.org
3. CITES (December, 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. Palm and Cycad Societies of Australia (PACSOA) (December, 2009)
   http://www.pacsoa.org.au/cycads/Encephalartos/inopinus.html
6. PlantZAfrica (February, 2009)
   http://www.plantzafrica.com/plantefg/encephinopin.htm
7. The Cycad Pages (December, 2009)
   http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/index.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.