Pollen morphology of the Megamexican cycads reveals the potential of morphometrics to identify cycad genera

keywords: Cycadales, Mexico, pollen morphology, taxonomy, Zamiaceae


Background: Although pollen morphology has always been an important tool in plant systematics, the possibility of distinguishing between related taxa is still debated. A difficult case is the cycads, where their morphology and small size is very similar. Pollen morphology has been important in plant systematics and determination at the species level is possible depending on the group. Controversial cases are the cycads, where their small pollen and smooth sculpture when observed under light microscopy present few useful characters for separation at the species level.

Question: Will cycad pollen morphometry be useful to distinguish taxa?

Study species: 15 species within the genera Ceratozamia, Dioon and Zamia were investigated with five species of each genus.

Methods: Pollen was obtained from both live specimens from the Clavijero Botanic Garden of the Instituto de Ecología, A.C., as well as herbarium specimens. Acetolyzed pollen was used for descriptions and morphometry, and non-acetolyzed pollen for SEM images.

Results: The thickness of the exine and pollen sculpture of Dioon differed from that of Ceratozamia and Zamia thus allowing its identification. The pollen morphology of Ceratozamia and Zamia is very similar and therefore difficult to distinguish between species.

Conclusions: The thicker exine of Dioon allows its pollen to be distinguished from the other two genera. Morphometric methods must be applied to distinguish pollen between species of Ceratozamia and Zamia.


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Author Biography

Andrew P. Vovides, Instituto de Ecología, A.C.

Red de Biología Evolutiva, Investigador Titlar C

Curador del Jardín Botánico Fco. J. Clavijero

Pollen morphology of the Megamexican cycads reveals the potential of morphometrics to identify cycad genera


Audran JC. 1970a. Structure de la paroi pollinique du Ceratozamia mexicana (Cycadacées) étudiées aux microscopes photonique et électronique après acétolyse ménagée. Comptes rendus de l'Académie des sciences 270: 1455-1457.
Audran JC. 1970b. Sur l'ultrastructure de la paroi pollinique chez le Ceratozamia mexicana
(Cycadacées). Pollen et Spores 12: 485-511.
Audran JC., Masure E. 1976. Precisions sur L' infrastructure de L' exine chez les cycadales prespermaphytes. Pollen et spores 18: 5-26.
Audran JC., Masure E. 1977. Contribution a la connaissance de la composition des sporodermes chez les Cycadales prespermaphytes etude en microscopie electronique a transmission M.E.T. et a balayage M.E.B. Palaeontographica 162: 115-158.
Audran JC., Masure E. 1978. La sculpture et l'infrastructure du sporoderme de Gingko biloba comparées a celles des enveloppes polliniques des Cycadales. Rev. Palaeobotany and Palynology 26: 363-387.
Bolinder K., Norbäck Ivarsson L., Humphreys AM., Ickert-Bond SM., Han F., Hoorn C., Rydin C. 2016. Pollen morphology of Ephedra (Gnetales) and its evolutionary implications. Grana 55: 24-51. https://doi.org/10.1080/00173134.2015.1066424
Bouchal JM., Denk T. 2020. Low taxonomic resolution of papillate Cupressaceae pollen (former Taxodiaceae) impairs their applicability for palaeo-habitat reconstruction. Grana 59: 71-93. https://doi.org/10.1080/00173134.2019.1701704
Brongniart AT. 1846. Note sur un nouveau genre de Cycadées du Mexique. Annales des Sciences Naturelles, Partie Botanique series 5: 5-9.
Calonje M., Stevenson D., Osborne R. The World List of Cycads, online edition [Internet]. 2013–2019. [cited 2019 Feb 13]. Available from: http://www.cycadlist.org.
Chamberlain CJ. 1912. Morphology of Ceratozamia. Botanical Gazette 53: 1-19. https://www.jstor.org/stable/2467364.
Christenhusz MJM. Reveal JL., Farjon A., Gardner MF., Mill RR. Chase MW. 2011. A new classification and linear sequence of extant gymnosperms. Phytotaxa 19: 55-70. ISSN 1179-3155.
Dehgan B., Dehgan NB. 1988. Comparative pollen morphology and taxonomic affinities in Cycadales. American Journal of Botany 75: 1501-1516. https://doi.org/10.1002/j.1537-2197.1988.tb11224.x
De Luca P., Sabato S., Vázquez Torres M.1981. Dioon merolae (Zamiaceae), a new species from Mexico. Brittonia 33: 179-185. https://doi.org/10.2307/2806317.
De Luca P., Sabato S., Vázquez Torres M.1984. Dioon tomasellii (Zamiaceae), a new species with two varieties from western Mexico. Brittonia 36: 223-227.
Dyer WTT. 1882-1886. Cycadaceae. Biologia Centrali-Americana 3: 190–195. http://biodiversitylibrary.org/bibliography/730
Erdtman G. 1965. Pollen and spore morphology/plant taxonomy: Gymnospermae-Bryophytae.
Stockholm. Almquist & Wiksell. https://biodiversitylibrary.org/permissions.

Frederiksen NO.1978. Preservation of Cycad and Ginkgo pollen. Review of Palaeobotany and Palynology 25: 163-179. ISSN 00346667.
Halbritter H., Ulrich S., Grímsson F., Weber M., Zetter R., Hesse M., Buchner R., Svojtka M., Frosch-Radivo A. 2018. Illustrated pollen terminology. Cham. Springer. ISBN 978-3-319-71365-6.
Johnson LAS. 1959. The families of cycads and the Zamiaceae of Australia. Proceedings of the Linnean Society of New South Wales 81: 64-117. https://biodiversitylibrary.org/permissions
Kremp GOW. 1965. Morphological Encyclopedia of Palynology. Tucson. The University of Arizona Press. ISBN-10: 0816540233
Kuhn M. 2008. Building Predictive Models in R Using the caret Package. Journal of Statistical Software, 28(5), 1 - 26. doi:http://dx.doi.org/10.18637/jss.v028.i05
Lindley J. 1843. Dion edule. Edward's Botanical Register 29: 59-60.
Linneus f. 1789. Zamia furfuracea. Hortus Kewensis (Aiton) 3: 477.
Ludlow-Wiechers B., Ayala-Nieto M.L.1983. Catálogo palinológico para la Flora
de Veracruz. No. 14. Familia Taxodiaceae. Biotica 8: 309-314.
Moore PD., Webb JA.1978. An lllustrated Guide to PolIen Analysis. London. Hodder &
Stoughton. https://doi.org/10.1007/BF02909461.
Nagalingum NS., Marshall CR., Quental TB., Rai HS., Little DP., Mathews S. 2011. Recent synchronous radiation of a living fossil. Science 334: 796-799. DOI: 10.1126/science.1209926.
Pérez-Farrera MA., Vovides AP., Iglesias C. 1999. A new species of Ceratozamia (Zamiaceae, Cycadales) from Chiapas, Mexico. Novon 9: 410-413. DOI: 10.2307/3391741.
Rettig E. 1896. Die cycadeen des botanischen gartens in Petersburg. Gartenflora 45: 148-149. ISSN 0177.0349.
• Rzedowski J. 1991. Diversidad y orígenes de la flora fanerogamica de México. Acta Botánica Mexicana 14: 3-21. https://doi.org/10.21829/abm14.1991.611.
• Salas-Leiva DE., Meerow AW., Calonje M., Griffith MP., Francisco-Ortega J., Nakamura K.,
Stevenson DW., Lewis CE., Namoff S., 2013. Phylogeny of the cycads based on multiple single-copy nuclear genes: congruence of concatenated parsimony, likelihood and species tree inference methods. Annals of Botany 112: 1263-1278. https://doi:10.1093/aob/mct192.
Schutzman B. 1984. A new species of Zamia L. (Zamiaceae, Cycadales) from Chiapas, Mexico. Phytologia 55: 299-304. ISSN: 0031-9430.
Standley PC., Williams LO. 1951. Dioon mejiae. Ceiba 1: 36-38. ISSN 0008-8692.
Stevenson, DW., Sabato S., Moretti A., De Luca P. 1995-96. What is Zamia fischeri Miquel? Delpinoa 37-38: 9-17. ISSN 0416-928X.
Tekleva MV., Polevova SV., Zavialova NE. 2007. On some peculiarities of sporoderm structure in members of the Cycadales and Ginkgoales. Paleontological Journal 41: 1162-1178. https://doi.org/10.1134/S0031030107110159.
Vovides AP., Rees JD., Vazquez Torres M. 1983. Zamiaceae. In: Gomez-Pompa, editor. Flora de Veracruz, Fasc. 26: 1-31 INIREB, Xalapa. ISBN 84-89600-04-X.
Vovides AP., Avendaño S., Pérez-Farrera MA., González-Astorga J. 2008. A new species of Ceratozamia (Cycadales, Zamiaceae) from Veracruz, Mexico. Novon 18: 109-114. https://doi.org/10.3417/2006063.
Vovides AP., Avendaño S., Pérez-Farrera MA., Stevenson DW. 2012. What is Ceratozamia brevifrons (Zamiaceae)? Brittonia 64: 35-42. https://doi.org/10.1007/s12228-011-9199-8.
Whitehead DR., Langham EJ. 1965. Measurement as a means of identifying fossil
maize pollen. Bulletin of the Torrey Botanical Club 92: 7-20.

Whitehead DR., Sheenhan MC. 1971. Measurement as a means of identifying fossil maize pollen.II. The effect of the slide thickness. Bulletin of the Torrey Botanical Club 98: 268-271. https://doi.org/10.2307/2483626.
How to Cite
Vovides, A. P., Guevara, R., Coiro, M., Galicia, S., & Iglesias, C. (2020). Pollen morphology of the Megamexican cycads reveals the potential of morphometrics to identify cycad genera. Botanical Sciences, 99(1), 182-197. https://doi.org/10.17129/botsci.2696