Lebombo cycad  (Encephalartos senticosus)

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

Described in 1996 after it was split from Encephalartos lebomboensis (2) (4), the Lebombo cycad is one of the most cultivated cycads in South Africa (5) (6). The Lebombo cycad grows up to four metres tall and produces as many as eight stems from a single plant (2). Like all cycads, the stems are mainly comprised of soft, pithy storage tissue protected by a hard layer of old leaf bases (7). The bright green leaves may reach up to 1.5 metres long, and are typically recurved towards the tips (2) (4). Whereas E. lebomboensis usually only has solitary cones, or sometimes pairs, the Lebombo cycad may have multiple cones to a stem (2) (6), with up to four, orange-yellow cones on male plants, and up to three, apricot-yellow cones on female plants (2).

Encephalartos senticosus occurs in the Lebombo Mountains of north-eastern KwaZulu-Natal and Swaziland (1) (2).

Found in dry shrubby scrub on rocky slopes and cliffs (4).

Cycads are long-lived, slow growing plants that always occur as individual male or female plants (4) (7). There is no way of determining the sex of a cycad until it begins to produce its first cone (7). For a long time cycads were thought, like cone-producing conifers, to be entirely wind pollinated (8). However, studies now suggest that the vast majority, if not all cycads, are actually pollinated by insects or more specifically weevils (4) (7) (8). To attract pollinators, male and female cones produce powerful odours, usually in the early morning or evening (7). 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 (7) (9).

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 (4).

Like many other South Africa cycad species, the Lebombo cycad is most threatened by illegal harvesting (2) (10).

There are not known to be any specific conservation measures in place for the Lebombo cycad, but it is known to occur in several protected reserves (2), and 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:

• 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/