PDFs of my publications are also available through my Google Scholar profile or my ResearchGate!
2019
A global phylogeny of Stegnogramma ferns (Thelypteridaceae): generic and sectional revision, historical biogeography and evolution of leaf architecture. Li-Yaung Kuo, Yi-Hang Chang, Yu-Hsuan Huang, Weston Testo, Atsushi Ebihara, Germinal Rouhan, Luis Quintanilla, James Watkins, Yao Moan Huang, Fay-Wei Li. Cladistics DOI:L10.1111/cla.12399 (early view)
The rise of the Andes promoted rapid diversification in Neotropical Phlegmariurus (Lycopodiaceae). Weston Testo, Emily Sessa, and David Barrington. New Phytologist DOI:10.1111/nph.15544 (PDF)
*Also, a really nice commentary on our article in the same issue by lobeliologist Laura Lagomarsino, available here!
2018
Overcoming among-lineage rate heterogeneity to infer the divergence times and biogeography of the clubmoss family Lycopodiaceae. Weston Testo, Ashley Field, and David Barrington. Journal of Biogeography 45: 1929-1941. (PDF)
Are rates of species diversification and body size evolution coupled in the ferns? Weston Testo and Michael Sundue. American Journal of Botany 105: 525-535 (PDF) **(Invited contribution to special issue "Using and Navigating the Plant Tree of Life")
*A contribution to the ongoing debate about the importance of shifts in body size evolution as drivers of species proliferation: we find no evidence of body size evolution being correlated with rates of diversification across the ferns.
Novelties in Costa Rican Pityrogramma (Pteridaceae): a new species and a new hybrid from the Osa Peninsula. Weston Testo. American Fern Journal 108: 27-33. (PDF)
Target sequence capture of nuclear-encoded genes for ferns. Paul Wolf, Tanner Robison, Matthew Johnson, Michael Sundue, Weston Testo, Carl Rothfels. Application in Plant Sciences e01148 (PDF).
Phylogenetic systematics, morphological evolution, and natural groups in Neotropical Phlegmariurus (Lycopodiaceae). Weston Testo, Benjamin Øllgaard, Ashley Field, Thaís Almeida, Michael Kessler, David Barrington. Molecular Phylogenetics and Evolution 125:1-13 (PDF).
*This was the first chapter of my PhD dissertation to be published. I am excited about this work because it demonstrates the prevalence of convergent evolution in this group of clubmosses and proposes an updated classification of the clade based on phylogenetic and morphological data.
Geometry, allometry and biomechanics of fern leaf petioles: their significance for the evolution of functional and ecological diversity within the Pteridaceae. Jennifer Mahley, Jarmila Pittermann, Nick Rowe, Alex Baer, James Watkins, Eric Schuettpelz, James K Wheeler, Klaus Mehltreter, Michael Windham, Weston Testo, James Beck. Frontiers in Plant Sciences 9: 1-16. (PDF)
2017
Diplazium hybrids involving D. plantaginifolium and D. ternatum from Mexico and Central America. Weston Testo, Michael Sundue, Alejandra Vasco. Brittonia 69: 295-306. (PDF)
*It was a lot of fun to develop the ideas presented in this paper - we describe two new hybrids in the the genus and scratch the surface of the complex history of hybridization in Diplazium. There is still a lot of work to be done on reticulate evolution in tropical ferns and lycophytes!
The evolution of aluminum accumulation in ferns and lycophytes. Marco Schmitt, Klaus Mehltreter, Michael Sundue, Weston Testo, Toshihiro Watanabe, Steven Jansen. American Journal of Botany 104: 573-583. (PDF)
Phlegmariurus lehnertii, a new name for Phlegmariurus lancifolius (Lycopodiaceae). Weston Testo. Phytotaxa 297: 289-290. (PDF)
2016
A 4000-species dataset provides new insight into the evolution of ferns. Weston Testo, Michael Sundue. Molecular Phylogenetics and Evolution 105: 200-211. (PDF)
*Using a super-matrix approach, we assembled a phylogeny that includes ca. 40% of known fern species and incorporated a large fossil dataset to infer the timing of fern diversification. I think the important take-away here is that we provide evidence that many fern groups originated earlier than previous studies had suggested - subsequent studies such as Morris et al. (PNAS, 2018) and Lehtonen et al. (Scientific Reports, 2017) have corroborated our findings, which is exciting!
Huperzia continentalis (Lycopodiaceae), a new species of gemmiferous clubmoss separated from Huperzia haleakalae. Weston Testo, Arthur Haines, Arthur Gilman. Systematic Botany 41: 894-901. (PDF)
*A simple taxonomic fix for a complex and long-standing problem. Turns out Huperzia haleakalae is a (likely extinct) Hawaiian endemic and we had been misapplying that name to North American plants for decades.
On the widespread capacity for, and functional significance of, extreme inbreeding in ferns. Emily Sessa, Weston Testo, James Watkins. New Phytologist 211: 1108-1119. (PDF)
Molecular phylogenetics and the morphology of the Lycopodiaceae subfamily Huperzioideae supports three genera: Huperzia, Phlegmariurus and Phylloglossum. Ashley Field, Weston Testo, Peter Bostock, Joseph Holtum, Michelle Waycott. Molecular Phylogenetics and Evolution 94: 635-657. (PDF)
Parapolystichum novoguineense (comb. nov.; Dryopteridaceae) from New Guinea. Michael Sundue and Weston Testo. Phytotaxa 243: 193-196. (PDF)
A community-derived classification of extant ferns and lycophytes. Eric Schuettpelz, Harald Schneider, Alan R Smith, Peter Hovenkamp, ... Weston Testo, ... Xin-Mao Zhou [94 contributors]. Journal of Systematics and Evolution 54: 563-603. (PDF)
*It was a great pleasure to be part of this large effort, which was headed up principally by Eric Schuettpelz. Ferns and lycophytes were in need of an updated, consistent, and sensible classification system; I think we achieved that here.
2015
Morphological innovation, ecological opportunity, and the radiation of a major vascular epiphyte lineage. Michael Sundue, Weston Testo, Tom Ranker. Evolution 69: 2482-2495. (PDF)
Use of gemma characters to identify North American Huperzia (Lycopodiaceae). Art Gilman, Weston Testo. American Fern Journal 105: 145-161. (PDF)
Pteris ×caridadiae (Pteridaceae), a new hybrid fern from Costa Rica. Weston Testo, James Watkins, Jarmila Pittermann, Rehman Momin. Brittonia 67: 138-143. (PDF)
An unusual form of Huperzia selago (Lycopodiaceae) and its implications for gemma homology in the genus. Weston Testo, Lynden Gerdes. American Fern Journal 105: 123-126. (PDF)
Dynamics of asymmetrical hybridization in North American wood ferns: reconciling patterns of inheritance with gametophyte reproductive biology. Weston Testo, James Watkins, David Barrington. New Phytologist 206: 785-795. (PDF)
*Interspecies sex, pheromones, and speedy sperm!
2014
Beyond antheridiogens: chemical competition between gametophytes of Polypodium appalachianum and Polypodium virginianum. Weston Testo, Matthew Grasso, David Barrington. Journal of the Torrey Botanical Society 141: 302-312. (PDF)
Primary hemiepiphytism in Colysis ampla (Polypodiaceae) provides new insight into the evolution of growth habit in ferns. Weston Testo, Michael Sundue. International Journal of Plant Sciences 175: 526-536. (PDF)
Understanding mechanisms of rarity in pteridophytes: Competition and climate change threaten the rare fern Asplenium scolopendrium var. americanum (Aspleniaceae). Weston Testo, James Watkins. American Journal of Botany 100: 2261-2270. (PDF)
*Work I did as an undergraduate student with Eddie Watkins at Colgate University. We demonstrate the sensitivity of this taxon's gametophyte to temperate and drought stress, as well as competition with co-occurring fern species!
2012
Influence of plant size on the ecophysiology of the epiphytic fern Asplenium auritum (Aspleniaceae) from Costa Rica. Weston Testo, James Watkins. American Journal of Botany 99: 1840-1846. (PDF)
2011
Comparative development and gametophyte morphology of the hart's-tongue fern, Asplenium scolopendrium L. Weston Testo, James Watkins. Journal of the Torrey Botanical Society 138: 400-408. (PDF)
In-situ gametophyte morphology of the tropical epiphyte Oleandra articulata. James Watkins, Weston Testo, Richard Merkhofer. American Fern Journal 101: 52-56. (PDF)
2019
A global phylogeny of Stegnogramma ferns (Thelypteridaceae): generic and sectional revision, historical biogeography and evolution of leaf architecture. Li-Yaung Kuo, Yi-Hang Chang, Yu-Hsuan Huang, Weston Testo, Atsushi Ebihara, Germinal Rouhan, Luis Quintanilla, James Watkins, Yao Moan Huang, Fay-Wei Li. Cladistics DOI:L10.1111/cla.12399 (early view)
The rise of the Andes promoted rapid diversification in Neotropical Phlegmariurus (Lycopodiaceae). Weston Testo, Emily Sessa, and David Barrington. New Phytologist DOI:10.1111/nph.15544 (PDF)
*Also, a really nice commentary on our article in the same issue by lobeliologist Laura Lagomarsino, available here!
2018
Overcoming among-lineage rate heterogeneity to infer the divergence times and biogeography of the clubmoss family Lycopodiaceae. Weston Testo, Ashley Field, and David Barrington. Journal of Biogeography 45: 1929-1941. (PDF)
Are rates of species diversification and body size evolution coupled in the ferns? Weston Testo and Michael Sundue. American Journal of Botany 105: 525-535 (PDF) **(Invited contribution to special issue "Using and Navigating the Plant Tree of Life")
*A contribution to the ongoing debate about the importance of shifts in body size evolution as drivers of species proliferation: we find no evidence of body size evolution being correlated with rates of diversification across the ferns.
Novelties in Costa Rican Pityrogramma (Pteridaceae): a new species and a new hybrid from the Osa Peninsula. Weston Testo. American Fern Journal 108: 27-33. (PDF)
Target sequence capture of nuclear-encoded genes for ferns. Paul Wolf, Tanner Robison, Matthew Johnson, Michael Sundue, Weston Testo, Carl Rothfels. Application in Plant Sciences e01148 (PDF).
Phylogenetic systematics, morphological evolution, and natural groups in Neotropical Phlegmariurus (Lycopodiaceae). Weston Testo, Benjamin Øllgaard, Ashley Field, Thaís Almeida, Michael Kessler, David Barrington. Molecular Phylogenetics and Evolution 125:1-13 (PDF).
*This was the first chapter of my PhD dissertation to be published. I am excited about this work because it demonstrates the prevalence of convergent evolution in this group of clubmosses and proposes an updated classification of the clade based on phylogenetic and morphological data.
Geometry, allometry and biomechanics of fern leaf petioles: their significance for the evolution of functional and ecological diversity within the Pteridaceae. Jennifer Mahley, Jarmila Pittermann, Nick Rowe, Alex Baer, James Watkins, Eric Schuettpelz, James K Wheeler, Klaus Mehltreter, Michael Windham, Weston Testo, James Beck. Frontiers in Plant Sciences 9: 1-16. (PDF)
2017
Diplazium hybrids involving D. plantaginifolium and D. ternatum from Mexico and Central America. Weston Testo, Michael Sundue, Alejandra Vasco. Brittonia 69: 295-306. (PDF)
*It was a lot of fun to develop the ideas presented in this paper - we describe two new hybrids in the the genus and scratch the surface of the complex history of hybridization in Diplazium. There is still a lot of work to be done on reticulate evolution in tropical ferns and lycophytes!
The evolution of aluminum accumulation in ferns and lycophytes. Marco Schmitt, Klaus Mehltreter, Michael Sundue, Weston Testo, Toshihiro Watanabe, Steven Jansen. American Journal of Botany 104: 573-583. (PDF)
Phlegmariurus lehnertii, a new name for Phlegmariurus lancifolius (Lycopodiaceae). Weston Testo. Phytotaxa 297: 289-290. (PDF)
2016
A 4000-species dataset provides new insight into the evolution of ferns. Weston Testo, Michael Sundue. Molecular Phylogenetics and Evolution 105: 200-211. (PDF)
*Using a super-matrix approach, we assembled a phylogeny that includes ca. 40% of known fern species and incorporated a large fossil dataset to infer the timing of fern diversification. I think the important take-away here is that we provide evidence that many fern groups originated earlier than previous studies had suggested - subsequent studies such as Morris et al. (PNAS, 2018) and Lehtonen et al. (Scientific Reports, 2017) have corroborated our findings, which is exciting!
Huperzia continentalis (Lycopodiaceae), a new species of gemmiferous clubmoss separated from Huperzia haleakalae. Weston Testo, Arthur Haines, Arthur Gilman. Systematic Botany 41: 894-901. (PDF)
*A simple taxonomic fix for a complex and long-standing problem. Turns out Huperzia haleakalae is a (likely extinct) Hawaiian endemic and we had been misapplying that name to North American plants for decades.
On the widespread capacity for, and functional significance of, extreme inbreeding in ferns. Emily Sessa, Weston Testo, James Watkins. New Phytologist 211: 1108-1119. (PDF)
Molecular phylogenetics and the morphology of the Lycopodiaceae subfamily Huperzioideae supports three genera: Huperzia, Phlegmariurus and Phylloglossum. Ashley Field, Weston Testo, Peter Bostock, Joseph Holtum, Michelle Waycott. Molecular Phylogenetics and Evolution 94: 635-657. (PDF)
Parapolystichum novoguineense (comb. nov.; Dryopteridaceae) from New Guinea. Michael Sundue and Weston Testo. Phytotaxa 243: 193-196. (PDF)
A community-derived classification of extant ferns and lycophytes. Eric Schuettpelz, Harald Schneider, Alan R Smith, Peter Hovenkamp, ... Weston Testo, ... Xin-Mao Zhou [94 contributors]. Journal of Systematics and Evolution 54: 563-603. (PDF)
*It was a great pleasure to be part of this large effort, which was headed up principally by Eric Schuettpelz. Ferns and lycophytes were in need of an updated, consistent, and sensible classification system; I think we achieved that here.
2015
Morphological innovation, ecological opportunity, and the radiation of a major vascular epiphyte lineage. Michael Sundue, Weston Testo, Tom Ranker. Evolution 69: 2482-2495. (PDF)
Use of gemma characters to identify North American Huperzia (Lycopodiaceae). Art Gilman, Weston Testo. American Fern Journal 105: 145-161. (PDF)
Pteris ×caridadiae (Pteridaceae), a new hybrid fern from Costa Rica. Weston Testo, James Watkins, Jarmila Pittermann, Rehman Momin. Brittonia 67: 138-143. (PDF)
An unusual form of Huperzia selago (Lycopodiaceae) and its implications for gemma homology in the genus. Weston Testo, Lynden Gerdes. American Fern Journal 105: 123-126. (PDF)
Dynamics of asymmetrical hybridization in North American wood ferns: reconciling patterns of inheritance with gametophyte reproductive biology. Weston Testo, James Watkins, David Barrington. New Phytologist 206: 785-795. (PDF)
*Interspecies sex, pheromones, and speedy sperm!
2014
Beyond antheridiogens: chemical competition between gametophytes of Polypodium appalachianum and Polypodium virginianum. Weston Testo, Matthew Grasso, David Barrington. Journal of the Torrey Botanical Society 141: 302-312. (PDF)
Primary hemiepiphytism in Colysis ampla (Polypodiaceae) provides new insight into the evolution of growth habit in ferns. Weston Testo, Michael Sundue. International Journal of Plant Sciences 175: 526-536. (PDF)
Understanding mechanisms of rarity in pteridophytes: Competition and climate change threaten the rare fern Asplenium scolopendrium var. americanum (Aspleniaceae). Weston Testo, James Watkins. American Journal of Botany 100: 2261-2270. (PDF)
*Work I did as an undergraduate student with Eddie Watkins at Colgate University. We demonstrate the sensitivity of this taxon's gametophyte to temperate and drought stress, as well as competition with co-occurring fern species!
2012
Influence of plant size on the ecophysiology of the epiphytic fern Asplenium auritum (Aspleniaceae) from Costa Rica. Weston Testo, James Watkins. American Journal of Botany 99: 1840-1846. (PDF)
2011
Comparative development and gametophyte morphology of the hart's-tongue fern, Asplenium scolopendrium L. Weston Testo, James Watkins. Journal of the Torrey Botanical Society 138: 400-408. (PDF)
In-situ gametophyte morphology of the tropical epiphyte Oleandra articulata. James Watkins, Weston Testo, Richard Merkhofer. American Fern Journal 101: 52-56. (PDF)