|Scientific Name:||Dioon holmgrenii|
|Species Authority:||De Luca, Sabato & Vázq.Torres|
|Red List Category & Criteria:||Endangered A4c; B1ab(iii,iv)+2ab(iii,iv) ver 3.1|
|Assessor(s):||Chemnick, J., Gregory, T. & Morales S.|
|Reviewer(s):||Donaldson, J.S. & Bösenberg, J.D.|
Classified as Endangered based on an estimated ongoing decline of >50% over three generations. Also qualifies under criterion B due to very small extent of occurrence, small number of locations and ongoing decline.
|Previously published Red List assessments:|
|Range Description:||This species is restricted to state of Oaxaca, Mexico. Plants occurs to the south west of San Gabriel Mixtepec.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Plants are known only from two (500 and 10,000 plants) colonies.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This species grows mainly in humid forest dominated by species of Pinus and Quercus. They are found on slopes with a north eastern exposure. Plants often grow in ravines in humus-rich soil.|
|Generation Length (years):||500|
|Major Threat(s):||These plants are affected by habitat destruction due to agriculture (corn, pastures) and also as a result of over-collecting.|
|Conservation Actions:||This species is listed on Appendix II of the CITES Appendices. Plants are protected by local communities.|
Chemnick, J., Gregory, T. and Morales, S. 2007. Email received in response to request for information.
Donaldson, J.S. (ed.). 2003. Cycads. Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK.
Hill, K.D. and Stevenson, D.W. 1998-2006. The Cycad Pages. Available at: http://plantnet.rbgsyd.gov.au/PlantNet/cycad/.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: http://www.iucnredlist.org. (Accessed: 2 September 2010).
Jones, D.L. 1993. Cycads of the World. Reed, New Holland, Frenchs Forest, N.S.W., Australia.
Whitelock, L.M. 2002. The Cycads. Timber Press, Portland, Oregon.
|Citation:||Chemnick, J., Gregory, T. & Morales S. 2010. Dioon holmgrenii. The IUCN Red List of Threatened Species 2010: e.T42129A10660365.Downloaded on 23 January 2017.|
|Feedback:||If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided|