On this page are listed cycad-related articles and publications. Click a link below to go directly to the subject area of your choice.

[ Biology/Anatomy/General Info ]  [ Taxonomy/Phylogenetics ] 
[ Biogeography ]  [ Ethnobotany ]  [ Toxins ]  [ Pests ]  [ Books for Sale ]

TCS Publications

Expanded Glossary of Cycad Terms

In 2009, TCS developed an expanded glossary of more than 1,200 cycad terms (using the Glossary of Terms Encountered in Cycad Systematics provided in Walters & Osborne [2004] as a foundation) as well as a fully illustrated glossary of more than 500 terms using cycad-specific examples. Click here for more information.

Etymological Compendium of Cycad Names

Also in 2009, TCS compiled a list of the etymologies (= meanings) of all valid cycad names. Click here to view this etymological compendium.

"Cycad Focus" Segments from the Cycad Newsletter

One of the consistent components of the Cycad Newsletter has been the "Cycad Focus" column, in which a different species of cycad is highlighted in each issue. These columns typically feature taxonomical, horticultural, phenological, and other information on the respective 'target' species. TCS will be making these in-depth "Cycad Focus" articles available online in an effort to provide quality educational information on cycads to a broader audience. Click here to go to the "Cycad Focus" articles on the Cycad Newsletter page.

Cycad Specialist Group Publications

The most important publication of the IUCN/SSC Cycad Specialist Group (CSG) released to date is the Cycad Action Plan. Published in 2003, this 86-page document brings together a collection of data and opinions on one of the world's most threatened plant groups and presents a series of action plans to promote their conservation. The Cycad Action Plan is available in PDF format from the IUCN/SSC website. The full citation for this document is as follows:

Donaldson, J.S. (ed.). 2003. Cycads: Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group. IUCN, Gland, Switzerland, and Cambridge, UK. ix + 86 pp.

Click the links below to download the entire document or parts thereof.

In 2003, CSG Chair, Dr. John Donaldson, produced the following article on cycad reserves for the 5^th World Parks Congress in Durban, South Africa:

• CSG Article on Cycad Reserves

Also in 2003, the CSG provided most of the data and analysis for the CITES Significant Trade Review of Cycads, compiled by TRAFFIC East/Southern Africa. The report is as follows:

• CSG 2003 Cycad Trade Review

The following news release on cycads was issued by the IUCN in 2003:

• IUCN 2003 News Release: Modern lifestyle threatens oldest seed plants on Earth

The following is a report submitted by the CSG Chair, Dr. John Donaldson, to the IUCN in 2004:

• CSG 2004 Report to IUCN

The World List of Cycads is maintained by the CSG and is published every three years. Click the link below to go to the most recent published version.

• Hill, K. D., D. W. Stevenson & R. Osborne. 2007. The world list of cycads. Proceedings of the 7th International Conference on Cycad Biology (CYCAD 2005), Xalapa, Mexico, January 2005. Memoirs of the New York Botanical Garden 97: 454-483.

In 2005, on the 20th anniversary of the World List of Cycads, Jody Haynes conducted a historical review of all published world lists and compiled a comprehensive comparison table listing every taxon ever included on a world list and indicating when each name was added and, in some cases, later removed. This document has never been formally published, but the most recent update (November 2009) is available for download using the link provided below.

• Haynes, J. L. 2009. World List of Cycads: A Historical Review. Unpublished. 37 pp.

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Other Publications

Cycad Biology, Anatomy & General Information

Below are some articles that provide either general information on cycads or more specific information on their biology or anatomy.

• Caldwell, O.W. & C.F. Baker. 1907. The identity of Microcycas calocoma. Botanical Gazette 43:330-335.

• Chamberlain, C.J. 1907. Preliminary note on Ceratozamia. Botanical Gazette 43:137.

• Chamberlain, C.J. 1919. The Living Cycads. University of Chicago Press, Chicago, IL. (5.8 Mb)

• Chamberlain, C.J. 1926. Hybrids in cycads. Botanical Gazette 81:401-418.

• Fisher, J.B. & T.E. Marler. 2006. Eccentric growth but no compression wood in a horizontal stem of Cycas micronesica (Cycadales). IAWA Journal 27(4):377-382. (450 Kb)

• Haynes, J.L. 2011. The Cycads I Have Seen (online presentation). The Cycad Society, 35 pp (unpublished). (6 Mb)

• Haynes, J.L. 2011. Rhopalotria mollis pollinator weevils on male Zamia furfuracea x floridana cone (video). The Cycad Society (unpublished). (5 Mb)

• Niklas, K.J., E.D. Cobb & T. Marler. 2006. A comparison between the record height-to-stem diameter allometries of pachycaulis and leptocaulis species. Annals of Botany 97:79-83.

• Siegel, L. 2007. Living fossils have hot sex. University of Utah news release referring to Dr. Irene Terry's article in Science (below).

• Smith, F.G. 1907. Morphology of the trunk and development of the microsporanium of cycads: Contributions from the Hull Botanical Laboratory XCI. Botanical Gazette 43:187-204. (1.2 Mb)

• Terry, I., G.H. Walter, C. Moore, R. Roemer & C. Hull. 2007. Odor-mediated push-pull pollination in cycads. Science 318:70.

• This link contains a video (in Spanish) of a visit to Microcycas calocoma in habitat in Cuba.

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Cycad Taxonomy & Phylogenetics

In 2002, a Cycad Classification Concepts workshop was held at Montgomery Botanical Center in Miami, FL, USA. The primary goal of the workshop was to ensure that cycad taxonomy and classification efforts are scientifically robust and standardized as much as possible. A 300-page volume entitled Cycad Classification: Concepts and Recommendations was published in 2004 from papers presented at this workshop. The full citation for this volume is as follows:

Walters, T. & R. Osborne (eds.). 2004. Cycad Classification: Concepts and Recommendations. CABI Publishing, Cambridge, MA. Included are contributions from leading researchers from Australia, China, Italy, Mexico, South Africa, Thailand, and USA. Although not an official CSG publication, this unique volume provides guidelines for the designation of species, species boundaries, and species groupings, thus clarifying what has long been a confused area of research. In support of future cycad studies, a glossary of terms used in cycad systematics , an extensive listing of available resources and contacts, and an updated World List of Cycads complete the volume.

Below are links to an unpublished manuscript entitled A Taxonomic Monograph of the Cycads, written by Charles J. Chamberlain just prior to his death in 1943. This is the first time this manuscript has ever been made available to the general public. It is obviously a draft and contains hand-written editorial comments by Arthrur W. Haupt of UCLA.

• Chamberlain, C. J. n.d. A taxonomic monograph of the cycads. Unpublished. (entire manuscript: 225 pages, 10 Mb)

  • Title Page / Preface / Contents (6 pages, 200 Kb)
  • Introduction (11 pages, 500 Kb)
  • Relationships and Distribution (3 pages, 160 Kb)
  • Morphology and Anatomy (22 pages, 1 Mb)
  • Introduction to Cycadaceae / Key to the Genera (3 pages, 120 Kb)
  • Cycas (30 pages, 1.3 Mb)
  • Stangeria (4 pages, 200 Kb)
  • Bowenia (6 pages, 280 Kb)
  • Dioon (12 pages, 520 Kb)
  • Macrozamia (26 pages, 1.1 Mb)
  • Encephalartos (35 pages, 1.4 Mb)
  • Microcycas (3 pages, 140 Kb)
  • Ceratozamia (10 pages, 420 Kb)
  • Zamia (43 pages, 1.7 Mb)
  • List of Figures (12 pages, 470 Kb)

The following document was associated with Chamberlain's manuscript. It was obviously written after his death, but the author is unknown.

• Synopsis of Living and Fossil Cycadaceae (5 pages, 250 Kb)

The following was one of the earliest attempts at addressing the phylogenetic relationships of the modern cycads.

• Chamberlain, C. J. 1915. A phylogenetic study of cycads. Proceedings of the National Academy of Sciences U.S.A. 1(2):86–90.

The link below is one of the most controversial works on cycads ever published. According to Dr. Paolo DeLuca, Schuster's lack of familiarity of both the living cycads and modern nomenclatural concepts caused “great confusion and instability in the nomenclature of cycads” (DeLuca, 1990). Written entirely in German, it is presented here solely as a historical piece. Be forewarned that the entire manuscript file is quite large and may not open properly; but it can be downloaded in its entirety. For reading online, it is recommended to use the individual page files.

• Schuster, J. 1932. Cycadaceae. Pp. 1-168, in A. Engler (ed.), Das Pflanzenreich 99(IV. 1). (entire manuscript: 174 pages, 27 Mb)

  • Title page - p. 24 (4 Mb)

  • Pp. 25-49 (4 Mb)

  • Pp. 50-74 (4 Mb)

  • Pp. 75-98 (4 Mb)

  • Pp. 99-121 (3.8 Mb)

  • Pp. 122-144 (3.6 Mb)

  • Pp. 145-168 (3.6 Mb)
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Below is an emended description of Dioon mejiae presented at the CYCAD 2005 conference in Xalapa, Veracruz, Mexico.

• Haynes, J. L. & M. A. Bonta. 2007. An emended description of Dioon mejiae Standl. & L.O. Williams (Zamiaceae). Proceedings of the 7th International Conference on Cycad Biology, Xalapa, Mexico, January 2005. Memoirs of the New York Botanical Garden 97: 418-443. (2.1 Mb)

Below are a couple articles that better elucidate the molecular relationships among the extant cycad genera.

• Zgurski, J.M., H.S. Rai, Q.M. Fai, D.J. Bogler, J. Francisco-Ortega & S.W. Graham. 2008. How well do we understand the overall backbone of cycad phylogeny? New insights from a large, multigene plastid data set. Molecular Phylogenetics & Evolution 47:1232-1237.

• Crisp, M.D. & L.G. Cook. 2011. Cenozoic extinctions account for the low diversity of extant gymnosperms compared with angiosperms. New Phytologist 192:997-1009.

Two new cycad species from Honduras were described in the June/September 2008 issue of the Cycad Newsletter -- representing the first ever species descriptions to be published there. They are available below:

• Haynes, J.L., L.M. Whitelock, B. Schutzman & R.S. Adams. 2008. A new endemic Ceratozamia from Honduras (Cycadales: Zamiaceae). Cycad Newsletter 31(2/3):16-21.

• Schutzman, B., R.S. Adams, J.L. Haynes & L.M. Whitelock. 2008. A new endemic Zamia from Honduras (Cycadales: Zamiaceae). Cycad Newsletter 31(2/3):22-26.

The following article discusses the taxonomic status and morphologic affinities of a recently described Encephalartos from Central Africa.

• Haynes, J.L. 2009. Encephalartos kanga Pócs & Q. Luke - A Newly Described ‘Red Cone Cycad’ from Tanzania. Cycad Newsletter 32(1):6-14.

In 2005, Tim Gregory, Jody Haynes, and Jeff Chemnick created a wonderfully illustrated poster and identification key that summarizes the vegetative traits most useful in identifying the known species of Dioon (right). Originally presented at the 7th International Conference on Cycad Biology (CYCAD 2005) in Xalapa, Veracruz, Mexico, this one-of-a-kind poster (which measures 24" x 36") has been printed on heavy glossy paper and made available for sale by TCS. Proceeds from the sale of the posters will go toward cycad research, conservation, and/or education. Click the link below to see the poster. Key to the Species of Dioon

 

In 2008, Jeff Chemnick, Tim Gregory, Jody Haynes, Miguel Angel Perez-Farrera, and Loran Whitelock created another wonderfully illustrated poster and identification key that summarizes the vegetative traits most useful in identifying the known species of Ceratozamia (see below). Originally presented at the 8th International Conference on Cycad Biology (CYCAD 2008) in Panama City, Panama, this one-of-a-kind poster (which measures 24" x 36") has been printed on heavy glossy paper and made available for sale by TCS. Proceeds from the sale of the posters will go toward cycad research, conservation, and/or education. Click the link below to see the poster. Key to the Species of Ceratozamia

Original Species Descriptions

Click here to see our database of 190+ original cycad species descriptions.

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Cycad Biogeography

Below is a new chapter on Central American cycad biogeography published in a book entitled Global Advances in Biogeography:

• Taylor, A.S., J.L. Haynes, D.W. Stevenson, G. Holzman & J. Mendieta. 2012. Biogeographic insights in Central American cycad biology. Pp. 73-98, In: Global Advances in Biogeography, L. Stevens (ed.), InTech Open Access Publisher, Rijeka, Croatia. (1.5 Mb)

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Cycad Ethnobotany

The following is a preliminary assessment of the impacts of harvest on the Indian endemic, Cycas circinalis, in the Nilgiri Biosphere Reserve in Western Ghats, South India. It was prepared in a collaborative effort by representatives of People and Plants International and Keystone Foundation:

• Harvest, Trade, and Conservation of the Endemic Multi-use Cycad, Cycas circinalis L., in the Nilgiri Biosphere Reserve, South India. (600 Kb)

And below is a Cycad Newsletter article written by the same authors and describing their continuing work on Cycas circinalis in India:

• Saneesh, C.S. & A. Varghese. 2007. Mutualistic relationships involving the endemic Cycas circinalis L.: Field notes from the Appankappu Forests, Nilambur, Kerala, India. Cycad Newsletter 30(4):28-29.

Below is a recent paper on the ethnobotany and conservation status of Dioon mejiae—known locally as ‘tiusinte’—in Honduras:

• Bonta, M. A., O. Flores Pinot, D. Graham, J. Haynes & G. Sandoval. 2006. Ethnobotany and conservation of tiusinte (Dioon mejiae Standl. & L.O. Williams, Zamiaceae) in Northeastern Honduras. Journal of Ethnobiology 26(2):228-257. (2.6 Mb)

The following is a recent article on the ethnobotany of Dioon merolae in Mexico:

• Pérez-Farrera, M.A. & A.P. Vovides. 2006. The ceremonial use of the threatened “espadaña” cycad (Dioon merolae, Zamiaceae) by a community of the central depression of Chiapas, Mexico. Bol. Soc. Bot. Méx. 78:107-113. (1.6 Mb)

Below is a list of vernacular (common) names for cycads around the world:

• Bonta, M. & R. Osborne. 2007. Cycads in the vernacular: A compendium of local names. Proceedings of the 7th International Conference on Cycad Biology, Xalapa, Mexico, January 2005. Memoirs of the New York Botanical Garden 97: 143-175.

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Cycad Toxins

• Brenner, E.D., D.W. Stevenson & R. W. Twigg. 2003. Cycads: Evolutionary innovations and the role of plant-derived neurotoxins. Trends in Plant Science 8:446-452.

• Marler, T. E., V. Lee, and C. A. Shaw. 2005. Cycad toxins and neurological diseases in Guam: Defining theoretical and experimental standards for correlating human disease with environmental toxins. HortScience 40(6):1598-1606. (1 Mb)

• Marler, T. E., V. Lee, and C. A. Shaw. 2005. Spatial variation of steryl glucosides in Cycas micronesica plants: Within- and among-plant sampling procedures. HortScience 40(6):1607-1611. (1 Mb)

• Marler, T. E., V. Lee, J. Chung, and C. A. Shaw. 2006. Steryl glucoside concentration declines with Cycas micronesica seed age. Functional Plant Biology 33:857-862.

• Marler, T. E., V. Lee, and C. A. Shaw. 2007. Storage does not influence steryl glucoside concentration in Cycas micronesica seeds. HortScience 42(3):626-628.

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Cycad Pests

• Marler, T. E., and R. Muniappan. 2006. Pests of Cycas micronesica leaf, stem, and male reproductive tissues with notes on current threat status. Micronesica 39(1):1–9.

• Cycad Aulacaspis Scale Information Page

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Books for Sale

Various books on cycads are available.

One of the newest books published is on the cycads of Vietnam. Osborne, R., K. D. Hill, H. T. Nguyen, and L. Phan Ke. 2007. Cycads of Vietnam. Published by R. Osborne & W. van Eeden. The book can be ordered online, or it can also be purchased locally in South Africa. Please click the book cover for more information on this book and how to purchase a copy.

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