Encephalartos horridus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Cycadopsida Cycadales Zamiaceae

Scientific Name: Encephalartos horridus (Jacq.) Lehm.
Common Name(s):
English Eastern Cape Blue Cycad
Encephalartos nanus Lehm. in Hoeven & De Vriese
Zamia horrida Jacq.
Taxonomic Notes: This species was described as Zamia horrida by Jaquin in 1801. It was later included in the genus Encephalartos by Lehmann in 1834.

Assessment Information [top]

Red List Category & Criteria: Endangered A2acd+4cd ver 3.1
Year Published: 2010
Date Assessed: 2009-10-31
Assessor(s): Donaldson, J.S.
Reviewer(s): Agenbag, L. & Bösenberg, J.D.
This species has declined across wide areas of its former range, mostly due to expanding urban settlements and collecting. Subpopulations near Port Elizabeth and between PE and Uitenhage no longer exist. Although extent of occurrence and area of occupancy are smaller than required for an Endangered listing status, the species is known from more than five locations. The listing of Endangered is based on population declines of more than 50% over the last three generations (600 years) and that this is likely to continue happening into the near future.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is distributed in xeric thicket vegetation between Port Elizabeth and Uitenhage and north of Uitenhage in the Eastern Cape, South Africa. Occurs from 100 to 400 m asl.
Countries occurrence:
South Africa (Eastern Cape Province)
Additional data:
Estimated area of occupancy (AOO) - km2:50
Number of Locations:10
Lower elevation limit (metres):100
Upper elevation limit (metres):400
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The exact number of plants is unknown. Although several subpopulations have been visited regularly, there may be many unknown plants in the dense bush where E. horridus occurs.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:3000-7000
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:E. horridus usually occurs in xeric thicket vegetation, often on rocky quartzite outcrops. The now extinct subpopulations north and west of Port Elizabeth probably occurred in Sandstone Fynbos.
Generation Length (years):200

Threats [top]

Major Threat(s): E. horridus is now extinct in several parts of its former range where it has been totally eliminated by urban development. Substantial numbers have also been removed by collectors in the past 50 years. It is difficult to estimate what proportion of plants have disappeared but it could be as high as 50%.

Conservation Actions [top]

Conservation Actions: This species is listed on Appendix I of the CITES Appendices. Populations are protected in the Springs Local Authority Nature Reserve near Uitenhage and on several private game reserves.

Classifications [top]

3. Shrubland -> 3.5. Shrubland - Subtropical/Tropical Dry
3. Shrubland -> 3.8. Shrubland - Mediterranean-type Shrubby Vegetation
0. Root -> 6. Rocky areas (eg. inland cliffs, mountain peaks)
1. Land/water protection -> 1.1. Site/area protection
4. Education & awareness -> 4.3. Awareness & communications

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
1. Residential & commercial development -> 1.1. Housing & urban areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Residential & commercial development -> 1.2. Commercial & industrial areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.2. Gathering terrestrial plants -> 5.2.1. Intentional use (species is the target)
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.1. Unspecified species
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
3. Monitoring -> 3.1. Population trends

♦  Pets/display animals, horticulture
 National : ✓  International : ✓ 

♦  Establishing ex-situ production *

Bibliography [top]

IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: (Accessed: 2 September 2010).

Kemp, M. 1986. Focus on Encephalartos horridus. Encephalartos 7: 8-13.

Citation: Donaldson, J.S. 2010. Encephalartos horridus. The IUCN Red List of Threatened Species 2010: e.T41905A10587904. . Downloaded on 22 August 2018.
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