Skip to main content
Leigh Johnson.jpg

Leigh Johnson

Assistant Director-Bean Museum
M. L. Bean Museum, Biology

4058 LSB
Provo, UT 84602

Biography

Teaching Interests

  • Plant Biology
  • Plant Diversity
  • Plant Classification & Identification
  • Systematics

Research Interests

  • Plant Systematics
  • Taxonomy
  • Phylogenetic Inference
  • Species Delimitation
  • Phylogeography
  • Conservation Genetics

Education

  • PhD, Botany, Washington State University, 1996
  • BS, Botany, Brigham Young University, 1991

Courses Taught

Winter 2019

  • BIO 230: Biological Diversity: Plants Section 001, 002, 003
  • BIO 494R: Mentored Research Section 007
  • BIO 699R: Master's Thesis Section 006

Fall 2018

  • BIO 430: Plant Classif. & Identif. Section 001
  • BIO 494R: Mentored Research Section 008
  • BIO 510: Biological Systemat Curation Section 001
  • BIO 559R: Adv Topics Ecology & Evolution Section 006
  • BIO 699R: Master's Thesis Section 007

Winter 2018

  • BIO 230: Biological Diversity: Plants Section 001, 002
  • BIO 699R: Master's Thesis Section 006

Fall 2017

  • BIO 430: Plant Classif. & Identif. Section 001

Research Interests

Plant Systematics, Taxonomy, Phylogenetic Inference, Species Delimitation, Phylogeography, Conservation Genetics

Teaching Interests

Plant Biology, Plant Diversity, Plant Classification & Identification, Systematics

Education

  • PhD, Botany , Plant Systematics, institution ( 1996-01-01 - 1996-12-31 )
  • BS, Botany , Biotechnology, institution ( 1991-01-01 - 1991-12-31 )

Professional Citizenship

  • Reviewer, Ad Hoc Reviewer, various journals, 2017-01-01 - 2017-12-31 - 2017-01-01 - 2017-12-31
  • Editor, Associate Editor, Botanical Society of America, 2017-05-01 - 2017-05-31 - 2017-11-01 - 2017-11-30
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2017-09-01 - 2017-09-30 - 2017-09-01 - 2017-09-30
  • Reviewer, Ad Hoc Reviewer, various journals, 2015-01-01 - 2015-12-31 - 2015-01-01 - 2015-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2015-09-01 - 2015-09-30 - 2015-09-01 - 2015-09-30
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2015-02-01 - 2015-02-28 - 2015-04-01 - 2015-04-30
  • Reviewer, Ad Hoc Reviewer, various journals, 2014-01-01 - 2014-12-31 - 2014-01-01 - 2014-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2014-02-01 - 2014-02-28 - 2014-03-01 - 2014-03-31
  • Reviewer, Ad Hoc Reviewer, various journals, 2012-01-01 - 2012-12-31 - 2012-01-01 - 2012-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2012-09-01 - 2012-09-30 - 2012-09-01 - 2012-09-30
  • Committee/Council Chair, American Society of Plant Taxonomists, 2011-09-01 - 2011-09-30 - 2012-08-01 - 2012-08-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2012-03-01 - 2012-03-31 - 2012-04-01 - 2012-04-30
  • Reviewer, Ad Hoc Reviewer, various journals, 2011-01-01 - 2011-12-31 - 2011-01-01 - 2011-12-31
  • Committee/Council Member, American Society of Plant Taxonomists, 2010-09-01 - 2010-09-30 - 2011-08-01 - 2011-08-31
  • Reviewer, Ad Hoc Reviewer, Rancho Santa Ana Botanic Garden, 2010-09-01 - 2010-09-30 - 2010-12-01 - 2010-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2010-01-01 - 2010-12-31 - 2010-01-01 - 2010-12-31
  • Reviewer, Ad Hoc Reviewer, various journals, 2010-01-01 - 2010-12-31 - 2010-01-01 - 2010-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2009-01-01 - 2009-12-31 - 2009-01-01 - 2009-12-31
  • Reviewer, Ad Hoc Reviewer, various journals, 2009-01-01 - 2009-12-31 - 2009-01-01 - 2009-12-31
  • Committee/Council Member, Botanical Society of America, 2008-09-01 - 2008-09-30 - 2009-08-01 - 2009-08-31
  • Editor, Associate Editor, American Society of Plant Taxonomists, 2005-10-01 - 2005-10-31 - 2009-03-01 - 2009-03-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation Grant Review, 2008-01-01 - 2008-12-31 - 2008-01-01 - 2008-12-31
  • Reviewer, Ad Hoc Reviewer, various journals, 2008-01-01 - 2008-12-31 - 2008-01-01 - 2008-12-31
  • Other, Fulbright Foundation, 2008-09-01 - 2008-09-30 - 2008-11-01 - 2008-11-30
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2007-01-01 - 2007-12-31 - 2007-01-01 - 2007-12-31
  • Reviewer, Ad Hoc Reviewer, various journals, 2007-01-01 - 2007-12-31 - 2007-01-01 - 2007-12-31
  • Reviewer, Ad Hoc Reviewer, Washington State University, 2006-09-01 - 2006-09-30 - 2006-12-01 - 2006-12-31
  • Reviewer, Ad Hoc Reviewer, various journals, grants, tenure review, 2006-01-01 - 2006-12-31 - 2006-01-01 - 2006-12-31
  • Editor, Associate Editor, Western North American Naturalist, 2004-01-01 - 2004-12-31 - 2006-01-01 - 2006-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2005-01-01 - 2005-12-31 - 2005-01-01 - 2005-12-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2005-01-01 - 2005-12-31 - 2005-01-01 - 2005-12-31
  • Reviewer, Ad Hoc Reviewer, various journals--see comments, 2005-01-01 - 2005-12-31 - 2005-01-01 - 2005-12-31
  • Editorial Review Board Member, Western North American Naturalist, 2003-01-01 - 2003-12-31 - 2005-01-01 - 2005-12-31
  • Reviewer, Ad Hoc Reviewer, Virgina Common Wealth University, 2001-09-01 - 2001-09-30 - 2001-12-01 - 2001-12-31
  • Committee/Council Member, Scientific Committee, North Carolina Department of Agriculture Plant Conservation Program, 1997-01-01 - 1997-12-31 - 1999-01-01 - 1999-12-31

Courses Taught

2020

  • BIO 494R: Section 011
  • BIO 430 : Section 001
  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 230 : Section 003
  • BIO 494R: Section 007

2019

  • BIO 699R: Section 007
  • BIO 494R: Section 008
  • BIO 430 : Section 001
  • BIO 494R: Section 007
  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 230 : Section 003
  • BIO 699R: Section 006
  • BIO 494R: Section 007

2018

  • BIO 559R: Section 006
  • BIO 510 : Section 001
  • BIO 699R: Section 007
  • BIO 494R: Section 008
  • BIO 430 : Section 001
  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 699R: Section 006

2017

  • BIO 430 : Section 001
  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 510 : Section 001

2016

  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 494R: Section 009
  • BIO 430 : Section 001
  • BIO 559R: Section 4
  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 494R: Section 009

2015

  • BIO 230 : Section 001
  • BIO 230 : Section 002
  • BIO 430 : Section 001
  • BIO 220B: Section 001
  • BIO 220B: Section 002
  • BIO 699R: Section 006
  • BIO 494R: Section 009

2014

  • BIO 510 : Section 001
  • BIO 494R: Section 009
  • BIO 430 : Section 001
  • BIO 220B: Section 002
  • BIO 494R: Section 008
  • BIO 559R: Section 006
  • BIO 220B: Section 001
  • BIO 220B: Section 002
  • BIO 494R: Section 009

2013

  • BIO 430 : Section 001
  • BIO 220B: Section 001
  • BIO 220B: Section 002
  • BIO 430 : Section 001

2012

  • BIO 510 : Section 001
  • BIO 494R: Section 017
  • BIO 220B: Section 001
  • BIO 220B: Section 002
  • BIO 494R: Section 011
  • BIO 430 : Section 001

2011

  • BIO 512 : Section 001
  • BIO 494R: Section 017
  • BIO 494R: Section 024
  • BIO 220B: Section 001
  • BIO 220B: Section 002
  • BIO 430 : Section 001

2010

  • BIO 510 : Section 001
  • BIO 494R: Section 017
  • BIO 494R: Section 008
  • BIO 699R: Section 015
  • BIO 494R: Section 026
  • BIO 430 : Section 001
  • BIO 430 : Section 002
  • BIO 430 : Section 003

2009

  • BIO 699R: Section 013
  • LFSCI 399R: Section 002
  • BIO 494R: Section 012
  • LFSCI 494R: Section 019
  • BIO 430 : Section 001
  • BIO 430 : Section 002
  • BIO 430 : Section 003

2008

  • BIO 510 : Section 001
  • BIO 699R: Section 013
  • LFSCI 494R: Section 004
  • BIOL 494R: Section 003
  • BIOL 494R: Section 011
  • INBIO 559R: Section 008
  • INBIO 699R: Section 015
  • BIOL 494R: Section 022
  • INBIO 494R: Section 022
  • INBIO 430 : Section 001
  • INBIO 430 : Section 002
  • INBIO 430 : Section 003
  • INBIO 331 : Section 001

2007

  • INBIO 512 : Section 001
  • BIOL 494R: Section 040
  • BIOL 494R: Section 015
  • INBIO 494R: Section 012
  • INBIO 559R: Section 006
  • INBIO 494R: Section 020
  • INBIO 430 : Section 001
  • INBIO 430 : Section 002
  • INBIO 430 : Section 003
  • INBIO 430 : Section 004
  • INBIO 331 : Section 001

2006

  • INBIO 510 : Section 001
  • INBIO 494R: Section 26
  • INBIO 331 : Section 001
  • INBIO 559R: Section 7
  • INBIO 799R: Section 1
  • INBIO 230 : Section 001
  • INBIO 230 : Section 002
  • INBIO 230 : Section 003
  • INBIO 432 : Section 001

2005

  • INBIO 559R: Section 007
  • INBIO 512 : Section 001
  • INBIO 699R: Section 001

2004

  • INBIO 559R: Section 002
  • INBIO 799R: Section 001
  • INBIO 698R: Section 001
  • INBIO 699R: Section 002
  • INBIO 131 : Section 001
  • INBIO 699R: Section 001
  • INBIO 432 : Section 001

Publications

  • Baranzelli MC, Issaly EA, Andrea-Gomez G, Johnson LA, Aguilar DL, Petrinovic IA, Rocamundi N, Service A, Cosacov A, Camps GA. August, 2020. Volcanism rather than climatic oscillations explains the shared phylogeographic patterns among ecologically distinct plant species in the southernmost areas of the South American Arid Diagonal.
  • Johnson LA. December, 2019. Phylogenetic and Taxonomic Complexity among the Vernal Pool Species and Near Relatives of Navarretia Section Navarretia. R.A. Schlising, E.E. Gottschalk Fisher, C.M. Guilliams, and B. Castro, editors. Chico, California: California State University.
  • Denham SS, Brignone NF, Johnson LA, Pozner RE. January (1st Quarter/Winter), 2019. Using integrative taxonomy and multispecies coalescent models for phylogeny reconstruction and species delimitation within the “Nastanthus–Gamocarpha” clade (Calyceraceae).
  • Rodríguez-Peña RA, Johnson RL, Johnson LA, Anderson CD, Ricks NJ, Farley KM, Robbins MD, Wolfe AD, Stevens MR. September 5, 2018. Investigating the genetic diversity and differentiation patterns in the Penstemon scariosus species complex under different sample sizes using AFLPs and SSRs. 6th ed.
  • Gowen D, Johnson LA. April (2nd Quarter/Spring) 10, 2018. Navarretia panochensis (Polemoniaceae), a new species from the Panoche Hills and Panoche Valley of the San Joaquin Desert, California.
  • Achimón F, Johnson LA, Cocucci AA, Sérsic AN, Baranzelli MC. January (1st Quarter/Winter) 17, 2018. Species tree phylogeny, character evolution, and biogeography of the Patagonian genus Anarthrophyllum Benth (Fabaceae).
  • Johnson LA, Gowen D. December 5, 2017. Ex uno, multis: taxonomic revision in Navarretia divaricata (Polemoniaceae) and the recognition of four additional cryptic or near-cryptic species.
  • Simpson MG, Johnson LA, Villaverde T, Guilliams CM. November 27, 2017. American Amphitropical Disjuncts: Perspectives from vascular plant analyses and prospects for future research.
  • Johnson LA, Porter JM. November 27, 2017. Fates of angiosperm species following long-distance dispersal: examples from American amphitropical Polemoniaceae.
  • Denham SS, Zavala-Gallo L, Johnson LA, Pozner RE. December 22, 2016. Insights into the phylogeny and evolutionary history of Calyceraceae.
  • Johnson LA, Gowen D, Johnson RL, Brabazon H, Goates ED. April (2nd Quarter/Spring) 20, 2016. Navarretia crystallina and N miwukensis (Polemoniaceae): new species endemic to California with affinity for soils derived from pyroclastic deposits. 3rd ed.
  • Nicola MV, Sede SM, Pozner R, Johnson LA. November, 2014. Phylogeography and palaeodistribution modelling of Nassauvia subgenus Strongyloma (Asteraceae): exploring phylogeographical scenarios in the Patagonian steppe.
  • Baranzelli MC, Johnson LA, Cosacov A, Sérsic AN. July (3rd Quarter/Summer), 2014. Historical and ecological divergence among populations of Monttea chilensis (Plantaginaceae), an endemic endangered shrub bordering the Atacama Desert, Chile.
  • Johnson LA, Gowen D, Jensen AB. April (2nd Quarter/Spring), 2013. Cryptic speciation: distinguishing serpentine affiliated sister species Navarretia paradoxiclara and N paradoxinota from N intertexta (Polemoniaceae).
  • Cosacov A, Johnson LA, Paiaro V, Cocucci AA, Cordoba FE, Sersic AN. January (1st Quarter/Winter), 2013. Precipitation rather than temperature influenced the phylogeography of the endemic shrub Anarthrophyllum desideratum in the Patagonian steppe.
  • Johnson LA, Chan LM, Pozner R, Glazier LD. June, 2012. Allotetraploids in Patagonia with affinities to western North American diploids: did dispersal or genome doubling occur first? .
  • Pozner R, Zanotti C, Johnson LA. January (1st Quarter/Winter), 2012. Evolutionary origin of the Asteraceae capitulum: insights from Calyceraceae. 1st ed.
  • Sersic AN, Cosacov A, Cocucci AA, Johnson LA, Pozner R, Avila LJ, Sites JW, Morando M. June, 2011. Emerging phylogeographic patterns of plants and terrestrial vertebrates from Patagonia. 2nd ed.
  • Johnson LA, Cairns-Heath H. September, 2010. Decrypting cryptic species: morphological and molecular evidence for recognizing Navarretia linearifolia as distinct from N sinistra (Polemoniaceae). 3rd ed.
  • Cosacov A, Sersic AN, Sosa V, Johnson LA, Cocucci AA. August, 2010. Multiple periglacial refugia in the Patagonian steppe and post-glacial colonization of the Andes: the phylogeography of Calceolaria polyrhiza.
  • Johnson LA, LC, Weese TL, Busby LD, McMurry SL. July (3rd Quarter/Summer), 2008. Nuclear and cpDNA sequences combined provide strong inference of higher phylogenetic relationships in the phlox family (Polemoniaceae).

Presentations

  • Johnson LA. Population-level sampling illuminates near-cryptic species diversity in Navarretia (Polemoniaceae). Protecting California’s diversity: genetic considerations for native planting and restoration. California is the center of diversity for many genera For Navarretia (Polemoniaceae), 91% of the recognized species and subspecies occur within California’s borders, and 57% are endemic to this state With 47 species currently recognized, Navarretia has increased greatly in number from the 28 that were recognized in the first edition of The Jepson Manual Four species were added as the result of molecular work that placed former members of Gilia within Navarretia, along with resurrecting a cryptic species long lost in synonymy Molecular data also contributed to one subspecies being returned to species status and another elevated to species status Thirteen additional species (10 of these found only in California) have been described as new These species have come to light largely through field work purposefully conducted to sample species broadly across their geographic range Continued field work combined with herbarium studies indicates additional diversity exists in several species-groups still being investigated Some of the taxonomic novelties enumerated above are geographically widespread while others are narrowly distributed; some are edaphic specialists while others are more generalists Most, however, are at least somewhat superficially similar to previously recognized species such that their taxonomic recognition has been previously overlooked. October, 2020.
  • Saunders TC, Porter JM, Johnson LA. Resolving Relationships in Aliciella subsection Subnuda. Botany 2020. July, 2020.
  • Stevens MR, Johnson RL, Meservey LM, Stettler JM, Anderson CD, Robbins MD, Johnson LA, Ricks NJ, Farley KM. Understanding the Penstemon scariosus complex. Utah Rare Plant Meeting. The Penstemon scariosus complex is found in the arid Uinta Basin and the surrounding mountainous region This species is currently divided into four varieties, albifluvis, cyanomontanus, garrettii, and scariosus Our study of the P scariosus complex found the present taxonomic keys misleading to use geography and morphological characteristics for delimiting varieties We used molecular data from 66 sets of fresh tissue sample and morphometric data from 180 herbarium sheets covering the entire range of all P scariosus varieties in this study We found that species determinations of herbarium samples were frequently based upon geographic location, as defined by current taxonomic keys However, when using the descriptive morphological traits described in those taxonomic keys, the varieties cyanomontanus, garrettii, and scariosus intermingled across the entire geographic range of all three varieties Furthermore, using molecular techniques, we found clear evidence of a genetically distinct population within the P scariosus complex Based on both molecular, and morphometric data, our current understating suggests that the P scariosus complex is best treated as two distinct species, P scarious and P albifluvis, and that P scariosus is comprised of two varieties (scariosus, and cyanomontanus) with var garrettii abandoned under synonymy with var scariosus Additionally, there is evidence of a possible third previously undescribed taxon that warrants further study. March, 2020.
  • Porter SJ, Johnson RL, Stettler JM, Stevens MR, Meservey L, Anderson CD, Johnson LA, Robbins MD, Ricks N. Molecular Characterization of White River Beardtongue, Penstemon scariosus var albifluvis. International Plant & Animal Genome XXVIII. Penstemon scariosus is a perennial plant species which thrives in the arid Uinta Basin region of the northern Colorado Plateau This species is currently divided into four varieties, P scariosus var albifluvis, P scariosus var cyanomontanus, P scariosus var garrettii, and P scariosus var scariosus Due to habitat destruction and fragmentation from oil and gas development and exploration, P scariosus var albifluvis is being considered for listing under the Endangered Species Act of 1973 At one point P scariosus var albifluvis was recognized as a distinct species but was reclassified to a variety of P scariosus based on similarities of plant morphology We hypothesize that P scariosus var albifluvis is reproductively isolated and genetically distinct from P scariosus To test this hypothesis, we collected tissue samples from 66 populations of currently recognized P scariosus varieties as well as four populations of P subglaber as an outlier We developed ten microsatellite markers for P scariosus and tested the allelic variation between these taxa Microsatellite data was analyzed using the program STRUCTURE to determine population structure We found evidence that P scariosus var albifluvis is genetically distinct from all other taxa and should be considered for reclassification as a species We also found another genetically distinct taxa within the P scariosus collections that is currently undescribed and found morphological and molecular evidence that P scariosus var cyanomontanus and P scariosus var garrettii are indistinguishable. January, 2020.
  • Johnson LA. Polemoniaceae - Plant taxonomy and identification workshop. Jepson Herbarium Workshops, 2019. 3 day intensive presentation and workshop with participants on identification of Polemoniaceae:

    The phlox family, Polemoniaceae, is not large compared to many flowering plant families, yet its members are frequently encountered in the spring and summer floras of diverse California plant communities Combined with a range of variation in floral form and a rich background of scientific inquiry, getting to know the genera and species of this family is rewarding California is particularly rich in Polemoniaceae diversity, with 17 of 22 temperate genera and about 70% of the temperate species occurring within its borders Key features for sight recognition of genera will be highlighted, including characters that distinguishAliciellaandSaltugiliafromGilia, andLinanthusfromLeptosiphon Features that delimit major groups within some of the more diverse genera such asGiliaandNavarrretiawill also be emphasized We will work through the keys using freshly collected material and recently pressed specimens that can be dissected as needed, with an emphasis on hands on keying using the second edition of The Jepson Manual The phylogenetic basis for the classification system used in TJM2 for Polemoniaceae, and some interesting examples of cryptic speciation within Californian Polemoniaceae will also be detailed While the instructor will provide both fresh and pressed specimens for dissection, participants are welcome to bring additional material and their own collections of Polemoniaceae for help with keying. June, 2019.
  • Saunders T, Porter JM, Johnson LA. Resolving Relationships in Aliciella subsection Subnuda: New Insights into Evolutionary Processes. Utah Rare Plant Meeting. Aliciellasubsection Subnudacontains seven species of perennial flowering plants: A tenuis, A caespitosa, A subnuda, A haydenii, A formosa, A cliffordii, and Gilia karenae, three of which are rare and others with fragmented, highly restricted distributions Previous molecular analyses of one nuclear and three chloroplast regions revealed an unexpected history of repeated hybridization and introgression within the subsection, including multiple cases of chloroplast capture by A tenuis To strengthen our understanding of species boundaries and evolutionary histories in these species, both the inter and intra-species sampling strategies were expanded over this past year Additionally, we increased our molecular data sampling via a next generation sequencing technique: restriction site associated DNA sequencing (rad-seq) While the rad-seq data analyses are still in progress, we report here our experience with generating next-generation sequencing data useful for informing conservation efforts from leaf tissues of different qualities These include herbarium material, leaf tissue collected in silica gel specifically for DNA analyses up to 15 years ago, and tissue newly collected in 2018, albeit in some cases from drought-stricken plants New insights into evolutionary processes across the entire subsection will be discussed. March, 2019.
  • Saunders T, Johnson LA. Resolving relationships in Aliciella subsection Subnuda (Polemoniaceae): high levels of chloroplast capture revealed by comparative DNA sequencing. Botany 2018. July, 2018.
  • Johnson LA. Vernal pool Navarretia and their near relatives: What we know and what we have yet to learn about relationships and genetic structure. Vernal Pool Landscapes: Past, Present, and Future. April, 2018.
  • Johnson LA, Saunders T, Jaramillo Z. Gilia karenae and Aliciella subsection Subnuda: current knowledge guiding this year's research. Utah Rare Plant Meeting. As recognized by its authors, Gilia karenae has close affinities with species of the segregate genus Aliciella Aliciella is only distantly related to Gilia and distinguished by a variety of morphological features that we briefly review With large DNA datasets representing the chloroplast genome and nuclear rDNA region already in place for the species of Aliciella subsection Subnuda, we added sequences from several individuals representing a number of populations of G karenae to explore its relationships to these species Unusually high levels of cpDNA variation forming four separate lineages within the single species, A tenuis, was unexpected, but can be explained by ancient introgression and chloroplast capture with related species Gilia karenae shows clear affinities for one of these four lineages and, in fact, cannot be distinguished from that lineage with our currently used markers We propose alternative hypotheses for species delimitation in this group and discuss the additional morphological and genetic study we will accomplish this year to test these alternatives rigorously. March, 2018.
  • Johnson LA. Cryptic species recognition and rare plant biology: Impractical taxonomic splitting or an inconvenient truth? . California Native Plant Society Conservation Conference 2018. Focused study of species is a fundamental activity of taxonomic research Such studies led to the discovery of new species throughout the 19th and 20th centuries and will continue to result in new species discovery via continued study and expanding methodologies for discerning biological uniqueness Many new species are labelled "cryptic" because they have been collected repeatedly but escaped taxonomic recognition due to similarity to other species Most of these taxa are not, however, truly cryptic That is, in most cases, these similar species can be distinguished morphologically by characters or character suites that were not previously noticed, appreciated, or emphasized The genus Navarretia (Polemoniaceae) has increased in size by ~ 25 percent over the past decade through renewed field and laboratory work including studies of both DNA and morphological variation New Navarretia include examples of species simply overlooked, those that may be considered "nearly cryptic", and some that are challenging to differentiate morphologically despite strong genetic differentiation Some new species are diploid, while others are polyploid Allopolyploids, formed by hybridization of distinct diploid species, bring their own set of challenges in that the available morphospace for visible physical differentiation is related to the degree of physical differentiation between the progenitor species Understanding the answers to two fundamental questions, ‘what is a species?' and ‘what are we trying to conserve?' is essential to working through the tension that can occur when biologically unique entities are difficult to differentiate in the field with a 10x hand lens . February, 2018.
  • Johnson LA. The value of specimen vouchering in determining biologically relevant taxon concepts . Utah Rare Plant Meeting. March, 2017.
  • Stevens MR, Harrison S, Ensign B, Robbins MD, Johnson RL, Johnson LA, Anderson CD, Ricks NJ, Farley KM. Breeding native flowers for drought tolerant urban landscapes: 2016 progress report. Annual WERA Meetings. October, 2016.
  • Ricks NJ, Stevens MR, Johnson RL, Johnson LA, Anderson CD, Robbins MD, Farley KM. The development and use of SSR markers for Penstemon scariosus, a species with horticultural potential. American Society for Horticultural Science Annual Conference. Penstemon scariosus var scariosus is horticulturally interesting because of its rather large showy blossoms, and its attractive emerald to dark green and somewhat compact foliage found in plants from some accessions Furthermore, this perennial plant has potential in xeric urban landscapes of the western US because it flourishes in arid and desolate environments at higher altitudes Finally, P scariosus var albifluvis is being considered for listing under the Endangered Species Act of 1973 due to recovery of hydrocarbon deposits located at sites where this variety is almost exclusively found Thus, the horticultural potential of var scariosus and the rarity of var albifluvis underlie the importance of understanding of the phylogenetic relationship within P scariosus To do so, we developed a set of ten new SSR (simple sequence repeat) markers specifically to study this species These markers were identified using a genomic reduction protocol in combination with next-generation sequencing of P scariosus Besides these ten markers, we tested all previously reported Penstemon SSRs and identified six additional markers that were robust, reliable, and polymorphic across a subset of 27 accessions including all four varieties of P scariosus and eight closely related taxa Of these 16 markers we selected ten that combined well together when labeled with either NED (yellow), 6-FAM (blue), or HEX (green) utilizing the ABI 3730xl with Gene Scan 500 ROX Size Standard We utilized those ten markers to test the individual samples of our collected 76 accessions The results of this study indicate that one taxon (P fremontii var glabrescens) is genetically distinct from P fremontii and was elevated to its own species Additionally, our data suggests that P scariosus var albifluvis is genetically independent and unique compared to the rest of the P scariosus varieties The intraspecific phylogenetic relationships morphological distinction of three remaining varieties of P scariosus (var cyanomontanus, garrettii, and scariosus) are less clear. August, 2016.
  • Rodriguez-Pena RR, Wolfe AD, Robbins MD, Johnson RL, Johnson LA, Anderson CD, Ricks NJ, Farley KM, Stevens MR. Population genetics and geographic patterns among varieties of Penstemon scariosus. Botanical Society of America Annual Conference. August, 2016.
  • Johnson LA. Stasis, evolution, and extirpation: exploring the fates of angiosperm species post long-distance dispersal with examples from Polemoniaceae . Botany 2016. July, 2016.
  • Johnson LA, Brabazon H. Population genetic structure across the range of Cycladenia humilis. Annual Utah Rare Plant Meeting. Cycladenia humilis is distributed in Utah/Arizona and California, with three recognized subspecies Using maternally inherited chloroplast DNA, and bi-parentally inherited low-copy nuclear DNA from five regions, we examine relationships and levels of genetic variation within and among populations across this species range Results indicate significant genetic structure between subspecies, generally high levels of heterozygosity, and geographic regions of interest with respect to genetic variation within variety jonesii. March, 2016.
  • Stevens MR, Johnson RL, Johnson LA, Robbins MD, Anderson CD, Ricks NJ, Farley KM. Unraveling the Penstemon scariosus complex using molecular markers – an update. Annual Utah Rare Plant Meeting. Penstemon scariosus Pennell is recognized as having a broad, complex range of morphological variability There are four botanical varieties of P scariosus recognized in the taxonomic key ‘A Utah Flora’ which are albifluvis, cyanomontanus, garrettii, and scariosus Of these, var albifluvis (White River beardtongue) is described as the most distinct in that treatment This taxon is found exclusively in northeastern Utah and slightly over the adjacent border of Colorado in Green River shale geological formations near the White River We have collected tissue samples from across the entire geographic range of P scariosus Variety albifluvis is geographically isolated from the three other varieties of P scariosus Because of its unique, limited habitat and the increasing efforts to recover hydrocarbons found in its surrounding geological formation, P scariosus var albifluvis has been and is currently being studied as a candidate taxon for listing under the Endangered Species Act of 1973 Understanding how unique P scariosus var albifluvis is compared to the other P scariosus varieties, as well as learning what the genetic relationships are within this taxon, are fundamental questions in this issue The objective of our study is to understand how each of these taxa interrelate to each other using ten molecular markers known as simple sequence repeats (SSRs) or also known as microsatellite markers Additionally, we would like to understand how P fremontii var glabrescens, from the Piceance Canyon, Rio Blanco Co, CO area relates to P scariosus Several specimens of P fremontii var glabrescens in the Brigham Young University Stanley L Welsh Herbarium from multiple collectors were mislabeled as P scariosus, which caused confusion in our early studies of P scariosus Our preliminary data clearly indicate that P scariosus var albifluvis falls within the broader taxon of P scariosus; but our data also suggest that it is distinct from the rest of the species Our data also clearly indicate that P fremontii var glabrescens is its own taxon distinct from P scariosus and P fremontii. March, 2016.
  • Johnson RL, Sadler C, Nufer J, Sanders K, Johnson LA. Physical and digital renovation of the vascular plant herbarium at Brigham Young University. Botany 2015. July, 2015.
  • Brabazon H, Johnson LA. Taxonomic delimitation of a rare, paleoendemic plant: historical phylogeography of Cycladenia humilis (Apocynaceae). Botany 2015. July, 2015.
  • Brazanelli MC, Gabriela F, Cosacov A, Johnson LA, Sersic AN. Vámonos pal Sur: patrones concordantes de crecimiento demográfico y expansión espacial a través del Monte Austral en Monttea aphylla (Plantaginaceae) usando filogeografía estadística y modelado de nicho ecológico. I Reunión Argentina de Biología Evolutiva. July, 2015.
  • Johnson RL, Yankee A, Johnson LA. Efforts to characterize the Penstemon scariosus complex; and a look at post-Lake Bonneville endemism in plants. Annual Utah Rare Plant Meeting. March, 2015.
  • Johnson LA. Look out for the little guys:  ID tips for some uncommon, small flowered Polemoniaceae newly recognized in Utah. Annual Utah Rare Plant Meeting. March, 2015.
  • Brabazon H, Last M, Chan LM, Johnson LA. Historical phylogeography and taxonomy of Cycladenia humilis (Apocynaceae) inferred from chloroplast and nuclear gene sequence data. Botany 2014. July, 2014.
  • Goates ED, Brabazon H, Johnson RL, Gowen D, Johnson LA. More than meets the eye: hidden diversity in Navarretia section Masonia (Polemoniaceae). Botany 2014. July, 2014.
  • Whipple CJ, Ross J, Jellen EN, Johnson LA. Gilia capitata (Polemoniaceae) as a model for genetic dissection of plant morphological evolution. Evolution Conference. July, 2013.
  • Johnson LA. Polemoniaceae - Plant taxonomy and identification workshop. Jepson Herbarium Workshops, 2013. 3 day intensive presentation and workshop with participants on identification of Polemoniaceae. June, 2013.
  • Johnson LA. Mussentuchit gilia. Utah Rare Plant Meeting. March, 2013.
  • Stevens MR, Dockter RB, Austin TL, Elzinga DB, Johnson LA, Maughan PJ, Geary BD, Tumbleson D, Franke J, Dockter. K. Understanding the phylogenetic relationships of 82 Penstemon taxa mostly from the Intermountain West using SNP markers . Annual WERA Meetings. October, 2012.
  • Cosacov A, Nicola M, Paiaro V, Sede S, Cocucci AA, Johnson LA, Pozner R, Sersic AN. Spatial analysis of genetic diversity and climatic niche modelling in Patagonian plant species: implications in conservation. Conservation in Patagonia: Integrating Science with Policy. September, 2012.
  • Nicola MV, Sede SM, Pozner R, Johnson LA. Modelado de la distribución geográfica actual y pasada de Mulinum spinosum (Apiaceae). XXXIII Jornadas Argentinas de Botánica. October, 2011.
  • Johnson LA. Herbarium Databasing: Basics, operation, and introduction to HerbACE. Consortium of Intermountain Herbaria Workshop. October, 2010.
  • Johnson LA. So you think you can dance? The tango of honey bee pollination. October, 2010.
  • Johnson LA. Urban jungles and plant discovery in the 21st century . May, 2010.
  • Johnson LA. Look out for the little guys: ID tips for new species and nomenclature of some small flowered Polemoniaceae. March, 2010.
  • Johnson LA. Elements of the Patagonian flora with origins in western North America: dispersal, speciation, and extirpation. Southern Connection VI Congress. February, 2010.
  • Pozner R, Johnson LA. Evolutionary origin of the Asteraceae capitulum: insights from Calyceraceae. Southern Connection VI Congress. February, 2010.
  • Cosacov A, Sersic AN, Johnson LA, Sosa V, Cocucci AA. Multiple periglacial refugia and post-glacial colonization of the Andes in the Patagonian herb Calceolaria polyrhiza. Southern Connection VI Congress. February, 2010.
  • Cosacov A, Sersic AN, Johnson LA, Sosa V, Cocucci AA. Testing the central-margin hypothesis into a phylogeographic framework in the Patagonian plant Calceolaria polyrhiza. Southern Connection VI Congress. February, 2010.
  • Johnson LA. The central role of homology in comparative biology. November, 2009.
  • Johnson LA. Herbarium databasing: needs, functionality, and alternatives. Consortium of Intermountain Herbaria Meeting. October, 2009.
  • Johnson LA. Species boundaries and hybridization - examples from the Phlox family. Claremont Graduate University. 2008.
  • Johnson LA. A crock of Gilia. Southern California Botanical Society Symposium. 2008.
  • Cosacov A, Sersic AN, Cocucci AA, Sosa V, Johnson LA. Large scale phylogeographic study of the Patagonian species Calceolaria polyrhiza Cav (Calceolariaceae). Botanical Society of America/American Society of Plant Taxonomists. July, 2008.
  • Wright AB, Cosacov A, Paiaro V, Sersic AN, Cocucci AA, Johnson LA. Phylogeographic patterns of fragmentation and expansion of the endemic perennial legume Anarthrophyllum desideratum (DC) Benth in Southern Patagonia. Botanical Society of America/American Society of Plant Taxonomists. July, 2008.
  • Johnson LA, LC, Burr KA. Relationships and reticulation among the vernal pool navarretias (Polemoniaceae) revisited: insights from single-copy nuclear gene PISTILLATA sequences. Botanical Society of America/American Society of Plant Taxonomists. July, 2008.
  • Johnson LA. Polemoniaceae - Identification workshop. 3rd Annual Pacific Northwest Herbarium Conference. wwwalbertsonedu/academics/biology/herbarium/conference/defaultasp. 2007.
  • Johnson LA, Pozner RE. Long distance relationships in Polemoniaceae: a tale of two species. American Society of Plant Taxonomists/Plant Biology Meetings. 2007.
  • Burr KA, Busby LD, Johnson LA. Relationships and reticulation among the vernal pool navarretias (Polemoniaceae). American Society of Plant Taxonomists/Plant Biology Meetings. 2007.
  • McArthur E, Johnson LA, Sanderson S, Hipkins V. Genetics and Introgression of Wildland Forb and Shrub Populations and Seedings. Annual Meeting of the Society for Range Management. 2007.
  • Johnson LA. Species boundaries & hybridization - examples from the phlox family. Biology Department. 2007.
  • Johnson LA. Systematic Botany in the Western US and Patagonia. Botany Department Seminar. 2007.
  • Johnson LA. Phylogeny & Homology in the Phlox Family. Graduate Program in Plant Biology Seminar. 2007.
  • Johnson LA. Species boundaries and hybridization - examples from the phlox family. University; Ecology, Evoluton, & Behavior Seminar. October, 2007.
  • Jensen AB, Lindquist SO, Pozner RE, Johnson LA. Calyx and trichome morphology in Navarrretia (Polemoniaceae). American Society of Plant Taxonomists/Plant Biology Meetings. July, 2007.
  • Johnson LA, Ferguson C, Patterson R, Wilken D. From its roots to its shoots: insights into diversification patterns and processes in the phlox family (Polemoniaceae). American Society of Plant Taxonomists-Evolution of Ericales Symposium. 2006.
  • McMurry SL, Johnson LA, Clark DJ, Etches R, Alonso J. Chloroplast phylogeography of the Mussentuchit Gilia (Aliciella tenuis, Polemoniaceae). American Society of Plant Taxonomists/Botanical Society of America. 2006.
  • Johnson LA. A wealth of floras and taxon concepts. Intermountain Herbarium Consortium. 2006.
  • Barnes D, Johnson LA. Reappraised pollen morphology and sectional classification in Navarretia (Polemoniaceae). American Society of Plant Taxonomists/Botanical Society of America. 2005.
  • Weese TL, Johnson LA. Relationships in the n=7 Loeselieae (Polemoniaceae) based on nuclear pistillata, ITS, and chloroplast trnL-F sequences. Society of Systematic Biologists/Evolution. 2005.
  • Barnes D, Johnson LA. Comparative micromorphology of the kelloggioid navarretias. American Society of Plant Taxonomist meetings. 2004.
  • Johnson LA, Wilken DH. Divergent and reticulate species relationships in a putatively monophyletic Collomia (Polemoniaceae). American Society of Plant Taxonomist meetings. 2004.
  • Johnson LA. Phylogenetic patterns and speciation in the Phlox family. 2004.
  • Matheson T, Johnson LA, MacArthur D, Johnson D, McMurray S. Assessing genetic variation within and between in natural and reseeded populations of two native forbs. Society for Range Mangament meetings. 2004.
  • Johnson LA. Are you my sister? Morphological and molecular evidence for cryptic speciation in the Phlox family. 2003.
  • Weese TL, Johnson LA. Character evolution within Saltugilia (Polemoniaceae) inferred from multiple gene phylogenies. Evolution Meetings. 2003.
  • Weese TL, Johnson LA. Taxonomic affinities of Saltugilia latimeri based on morphology and DNA sequence data. Granite Mtns 25th anniversary research symposium. 2003.
  • Johnson LA, Weese TL, Liljenquist N. Phylogenetic potential of IDH sequences in Polemoniaceae I: copy number and gene organization. American Society of Plant Taxonomists annual meetings. 2002.
  • Weese TL, Johnson LA, Dupree W. Phylogenetic potential of IDH sequences in Polemoniaceae II: levels of variability and correspondence with ITS and plastid genealogies. American Society of Plant Taxonomists annual meetings. 2002.
  • Johnson LA. Serendipity and sweat: elucidating the origins and relationships of a cryptic species pair in Polemoniaceae. 2002.
  • Johnson LA. Serendipity and sweat: elucidating the origins and relationships of a cryptic species pair in Polemoniaceae. 2002.
  • Holt K, Johnson LA, Porter JM, Gardner JL. External seed coat morphology of Gilia(Polemoniaceae) and segregate genera: comparison and correspondence with phylogenetic relationships. American Society of Plant Taxonomists annual meetings. 2001.
  • Johnson LA. Reprocal illumination: phylogenetic insights into the evolution of 18S sequences and the Phlox Family. University of Utah. 2001.
  • Porter JM, Johnson LA. Age and diversification and their implications for historical biogeography of Polemoniaceae. American Society of Plant Taxonomists annual meetings. 2000.
  • Schultz JL, Johnson LA, Ferguson C. Phlox idahoensis (Polemoniaceae): morphological and molecular approaches to conservation. American Society of Plant Taxonomists annual meetings. 2000.
  • Johnson LA. Sinister speciation: elucidating phylogeny and taxonomy in a cryptic species complex in Polemoniaceae. American Society of Plant Taxonomists annual meetings. 2000.
  • Weese TL, Johnson LA. Taxonomic limits and phylogenetic affinities of Saltugilia: molecular and morphological support for generic recognition apart from Gilia. American Society of Plant Taxonomists annual meetings. 2000.
  • Johnson LA. Herbarium use and plant identification resources. North Carolina State Cooperative Extension Service Annual Conference. 1999.
  • Johnson LA. Phylogeny and character evolution. Virginia Commonwealth University. 1999.
Leigh Johnson