Tzu-Tong Kao

Tzu-Tong Kao (高資棟), Ph.D. Candidate

I have broad interests in systematics, plant anatomy,  phylogenetics, evolutionary biology, and plant reproductive biology. My current dissertation research is focused on the evolution of notholaenids, a clade of resurrection (desiccation tolerant) ferns that have adapted to and diversified within the deserts of North America and Mexico. 

Evolution and function of “farina”

Farina is a layer of bright-colored lipophilic flavonoid exudates on the undersurfaces of sporophytic leaves and the margin of gametophytic prothallus. This character has evolved several times in xeric-adapted fern lineages in Pteridaceae and has been hypothesized to be an adaptation to drought that may reduce water loss from transpiration, protect dormant leaves from UV and heat damages, and/or inhabit the spore germination and gametophyte development of other competitors. My research is focus on resolving the phylogenetic relationships among farinose ferns, reconstructing the evolutionary history of farina, and investigating the evolutionary and ecophysiological roles of farina on adaptation to xeric environment.

Kao et al., 2019. Molecular Phylogenetics and Evolution 138: 139–155.

Infraspecific diversification of Notholaena standleyi in the deserts of North America and Mexico

Notholaena standleyi is one of the earliest divergent lineage of notholaenids ferns, widely distributed in the deserts of Southwest U.S. and northern Mexico.  A few “chemotypes” (infraspecific variants) were identified within species. These chemotypes has different farina colors, distribution ranges, and substrate preferences. In my dissertation, I integrate the data from molecular phylogeny, cytology, biochemistry, physiology, morphology/anatomy, and ecological niche modeling to revise the infraspecific circumscription, evaluate their molecular/cytological/biochemical/morphological/niche divergence, and resolve their reticulate evolutionary history.

Other topics

  • The evolution and function of epidermal silica idioblasts in ferns.
  • Reproductive biology of ferns and seed plants.
  • Systematics, anatomy, and conservative biology of tree ferns.
Room 348, Biological Sciences Building
Duke University, Durham NC, 27708
Education & Professional Experience

Duke University, Biology, Ph.D. student, 2013 – present
Taiwan Forest Research Institute, assistant, 2011-2013
Taiwan Society of Plant Systematics, assistant, 2010-2013
National Taiwan University, Ecology and Evolutionary Biology, M. Sc., 2009

National Taiwan University, Life Science, B. Sc., 2007


Kao, T.-T., C.J. Rothfels, A. Melgoza-Castillo, K.M. Pryer, and M.D. Windham. 2019. Infraspecific diversification of the star cloak fern (Notholaena standleyi) in the deserts of the United States and Mexico. In review.

Kao, T.-T., K.M. Pryer, F.D. Freund, M.D. Windham, and C.J. Rothfels. 2019. Low-copy nuclear sequence data confirm complex patterns of farina evolution in notholaenid ferns (Pteridaceae). Molecular Phylogenetics and Evolution 138: 139–155. DOI: 10.1016/j.ympev.2019.05.016.

GeorgeL.O., K.M. Pryer, T.-T. Kao, L. Huiet, & M.D. Windham. 2019. Baja: A new monospecific genus segregated from Cheilanthes s.l. (Pteridaceae). Systematic Botany 44: 471–482. DOI: 10.1600/036364419X15620113920536

Huiet, L., F.-W. Li, T.-T. Kao, J. Prado, A. R. Smith, E. Schuettpelz, & K. M. Pryer. 2018. A worldwide phylogeny of Adiantum(Pteridaceae) reveals remarkable convergent evolution in leaf blade architecture. Taxon 67: 488–502. DOI: 10.12705/673.3

Kuo, L.-Y., Y.-H. Chang, J.M.O. Glowienka, V.B. Amoroso, S.-Y. Dong, T.-T. Kao, C.-N. Wang, & W.-L. Chiou. 2016. A revised frameworkof Dryopterissubg. Nothoperanema (Dryopteridaceae) inferred from phylogenetic evidence, with descriptions of two new sections. Systematic Botany 41: 596–605. DOI: 10.1600/036364416X692334

Kao, T.-T., K.M. Pryer, M.D. Turner, R.A. White, & P. Korall. 2015. Origins of the endemic scaly tree ferns on the Galápagos and Cocos Islands. International Journal of Plant Sciences 176: 869–879. DOI: 10.1086/683303

Huang, Y.-M., V.B. Amoroso, F.P. Coritico, C.-W. Ko, T.-T. Kao, J.R. Callado, & W.-L. Chiou. 2015. Reproductive biology of Aglaomorpha cornucopia (Copel.) M.C. Roos, a rare and endemic fern from the Philippines. American Fern Journal 105: 31–44. DOI: 10.1640/0002-8444-105.1.31

Kao, T.-T., W.-L. Chiou, S.-Y. Hsu, C.-M. Chen, Y.-S. Chao, Y.-M. Haung. 2014. Hybrid origin of Nephrolepis xhippocrepicis Miyam (Nephrolepidaceae). International Journal of Plant Reproductive Biology 6: 1–14. Reprint PDF

Moore, S.-J., B.S. Parris, T.-T. Kao, P.-F. Lu, and W.-L. Chiou. 2013. Xiphopterella devolii (Polypodiaceae), a new species and newly recorded genus in Taiwan. Botanical Studies 54: 24. DOI: 10.1186/1999-3110-54-24

Kao, T.-T., S.-J. Chen, W.-L. Chiou, and L.-L. Kuo-Huang. 2008. Various microscopic methods for investigating the venuloid idioblasts of Pteris grevilleana Wall. Taiwania 53: 394–400. DOI: 10.6165/tai.2008.53(4).394

Master thesis

Kao, T.-T. 2009. A study of false veins and silica deposition types on fronds in Pteridaceae. Institute of Ecology and Evolutionary Biology, National Taiwan University. Reprint PDF (Appendix 5a, Appendix 5b)


紀瑋婷、高資棟。2018。植物藝術世界日。林業研究專訊。25(3): 47–49. Reprint PDF

黃曜謀、蔡心怡、高資棟、柯佳妏。2017。本土植物教學模式物種─水蕨。科學研習月刊。56–03。 Reprint PDF

黃曜謀、邱文良、陳俊銘、高資棟。2013。台北植物園區馬蹄腎蕨的研究與發現。林業研究專訊。20(3): 5355。 Reprint PDF

黃曜謀、高資棟、傅春旭。2011。談樹蕨瀕臨滅絕,臺灣博物季刊。112: 8083。 Link.


2017     NSF Doctoral Dissertation Improvement Grant, National Science Foundation ($20,670)